What Is Hypogonadism? Types, Causes & Diagnosis (2026)

Last updated: October 2, 2026

By the TRT Provider Guide Editorial Team · Last verified October 2026 · Educational information, not medical advice

Male hypogonadism is when your body does not make enough testosterone, enough sperm, or both because something is wrong in the testicles or in the brain signals that control them. Doctors diagnose testosterone-deficiency hypogonadism only when symptoms or signs fit and testosterone is consistently low on at least two properly timed early-morning blood tests.

That's the short answer to "what is hypogonadism." Here's the part most explanations skip: about 3 in 10 men whose first testosterone test looks low come back normal when they're retested (Endocrine Society). So if you just saw this word on a lab report, you may be earlier in the process than you think. Below, we'll show you exactly where you stand, what the numbers mean, and which step comes next.

This guide covers hypogonadism in adult men. Women can have hypogonadism too, and teens with delayed puberty are evaluated differently. We point you to the right resources for both further down.

TRT Provider Guide is the independent decision resource for testosterone replacement therapy — helping U.S. adults understand how low testosterone is evaluated, compare online and local care models and providers, and choose the next step that fits their health needs, fertility plans, budget, state, and care preferences, with every material claim verified and dated.

Three things that change the answer for you:

Only one test so far? You don't have a diagnosis yet. A second early-morning test comes first.
Want kids in the next few years? Talk about fertility before anyone talks about testosterone. Testosterone treatment can sharply suppress sperm production and can reduce sperm counts to zero in some men.
New severe headaches, vision changes, or milky nipple discharge? Get prompt in-person medical evaluation. These can point to a pituitary problem that needs its own workup. A sudden severe headache with vision loss needs emergency care.

Where are you in a hypogonadism diagnosis?

Most confusion about hypogonadism comes from mixing up four different things: having symptoms, getting one low result, having low testosterone confirmed, and knowing why it's low. We built this map so you can find your row. Each row shows what that step proves, what it doesn't, and what usually happens next.

Table 1: Where you are; What it proves; What it does NOT prove; Usual next step
Where you are	What it proves	What it does NOT prove	Usual next step
You have symptoms (low sex drive, fewer morning erections, low energy)	There may be a reason to check testosterone	That your testosterone is low. These symptoms have many other causes.	Ask a clinician whether testing makes sense
One low testosterone result	Your level was low on that one blood draw	That it stays low, or that you have hypogonadism	Repeat the test on a different morning
Two low early-morning results + matching symptoms	Low testosterone is confirmed. This meets the core diagnostic standard.	Why it's low, or which treatment fits	Test LH (and often FSH) to find the type
Type identified (primary or secondary)	Whether the pattern points mainly to the testicles or to hypothalamic/pituitary signaling	The exact cause in every case	Look for the cause: medicines, obesity, severe illness, pituitary or testicular disease, genetic conditions or injury; assess sleep apnea when relevant
Cause identified	Whether it might be reversible	Which treatment is right for you	Talk through fertility plans, health risks and goals
Treatment decision	That the plan matches the diagnosis	That TRT is the only option	Choose a care route and monitoring plan

Built by TRT Provider Guide from the Endocrine Society and American Urological Association diagnostic standards, October 2026.

What is hypogonadism, in plain English?

Hypogonadism means the gonads aren't functioning normally. In men, that can mean the testicles are not producing enough testosterone, enough sperm, or both because the problem is in the testicles themselves or in the hormone signals that control them. "Low T" is often used casually for low testosterone, but hypogonadism is a clinical diagnosis, not just one number on a lab sheet.

Break the word apart and it explains itself:

Hypo = low or under
Gonad = sex gland (in men, the testicles)
-ism = a condition

The Endocrine Society says hypogonadism should be diagnosed only in men who have symptoms or signs of testosterone deficiency together with unequivocally and consistently low testosterone, followed by evaluation to determine the cause (Endocrine Society guideline).

Testosterone does a lot of jobs. It supports sex drive and contributes to sexual function. It helps maintain muscle, bone, red blood cell production and body hair. Normal testicular testosterone signaling is also important for sperm production.

Is hypogonadism the same as low testosterone?

Not exactly. Low testosterone is a lab result. Hypogonadism is a diagnosis. To get the diagnosis, you need three things together: symptoms or signs that fit, testosterone that's low on repeat early-morning testing, and a clinician who's looked at the full picture (Endocrine Society guideline abstract).

You'll also see other names for the same idea. The American Urological Association (AUA) calls it testosterone deficiency. Lab portals and insurance forms may say testicular hypofunction. Ads usually just say low T.

Table 2: Term you might see; What it means
Term you might see	What it means
Low T	Everyday name for low testosterone
Testosterone deficiency	The AUA's term for the diagnosis
Male hypogonadism	The Endocrine Society's term for the diagnosis
Primary hypogonadism	The problem starts in the testicles
Secondary or central hypogonadism	The problem starts in the brain's signals
Hypergonadotropic hypogonadism	Another name for primary (the brain's signal hormones run high)
Hypogonadotropic hypogonadism	Another name for secondary (the brain's signal hormones run low)
Late-onset or age-related hypogonadism	A term used for symptomatic low testosterone that appears later in life; the Endocrine Society notes that age-related and functional labels can blur normal aging, illness and true hypogonadism
Functional hypogonadism	A term used for potentially reversible secondary low testosterone linked to factors such as obesity, severe illness or certain medicines; the label is not a substitute for finding the actual cause

Does hypogonadism only happen in men?

No. In women, hypogonadism means the ovaries are not producing the expected amount of sex hormones because of ovarian or brain-signaling problems. Normal menopause is age-related ovarian aging and is evaluated differently from pathologic hypogonadism, so this guide sticks to adult men. For a general overview that covers both sexes, see MedlinePlus.

If you're a parent of a teen who isn't showing signs of puberty, start with a pediatrician or a pediatric endocrinologist. The adult approach on this page doesn't apply.

How does your body make testosterone, and where does it break?

Testosterone is made in the testicles, but the order comes from the brain. The hypothalamus signals the pituitary gland, the pituitary sends hormones called LH and FSH to the testicles, and the testicles make testosterone and sperm. Hypogonadism happens when any link in that chain breaks.

Think of it as a three-step relay:

Hypothalamus (a small area at the base of your brain) releases a hormone called GnRH.
Pituitary gland (a pea-sized gland under the brain) answers by releasing LH (luteinizing hormone) and FSH (follicle-stimulating hormone).
Testicles respond. LH tells them to make testosterone. FSH helps them make sperm.

The chain also has a feedback loop, and it's the key to the whole diagnosis. When testosterone runs low, a healthy brain "shouts louder" by pushing out more LH.

If the testicles are the problem, the brain shouts but nobody answers. LH goes up. That's primary hypogonadism.
If the brain or pituitary is the problem, there's no shouting at all. LH stays low or oddly "normal." That's secondary hypogonadism.

That one blood test, LH, is how doctors tell the two main types apart (Merck Manual Professional).

What are the types of hypogonadism?

There are two main types. Primary hypogonadism means the testicles themselves aren't working well. Secondary hypogonadism, also called central or hypogonadotropic hypogonadism, means the brain isn't sending a strong enough signal. A blood test for LH usually shows which type you have.

Primary vs. secondary hypogonadism at a glance

Table 3: Primary hypogonadism; Secondary hypogonadism
	Primary hypogonadism	Secondary hypogonadism
Other names	Hypergonadotropic hypogonadism, testicular failure	Hypogonadotropic hypogonadism, central hypogonadism
Where the problem is	Testicles	Hypothalamus or pituitary gland (brain)
Testosterone	Low	Low
LH and FSH	High	Low, or "normal" when they should be high
Common causes	Klinefelter syndrome, undescended testicles, mumps infection of the testicles, injury, chemotherapy or radiation	Obesity, severe illness, opioids or corticosteroids, pituitary tumors, high prolactin, Kallmann syndrome
Fertility picture	Sperm production may be impaired; fertility treatment depends on the cause and how much testicular function remains	Depending on the cause, gonadotropin treatment can sometimes stimulate sperm production
Born with it or developed later?	Either	Either

Sources: Merck Manual Professional, Cleveland Clinic, Mayo Clinic.

What is primary hypogonadism?

Primary hypogonadism means the testicles can't make enough testosterone even though the brain is signaling them normally, or even harder than normal. It's sometimes called testicular failure. The most common genetic cause is Klinefelter syndrome (Merck Manual Professional).

What is secondary hypogonadism?

Secondary hypogonadism means the hypothalamus or pituitary is not sending enough signal to the testicles. You'll also see it called hypogonadotropic hypogonadism ("low gonadotropins," the family that LH and FSH belong to) or central hypogonadism. In adults, potentially reversible contributors include obesity, severe illness and certain medicines such as opioids or corticosteroids; other cases come from pituitary, hypothalamic or genetic disease (JAMA review, 2026).

What is mixed hypogonadism?

Sometimes both parts of the chain struggle at once. Some long-term illnesses can affect both the testicles and the brain's signal (Merck Manual Professional). Mixed cases usually belong with a specialist.

What is functional hypogonadism?

This term is used for potentially reversible secondary low testosterone without a fixed structural or genetic defect. A 2026 JAMA review identifies obesity, severe illness and certain medicines — including opioids and corticosteroids — among the most common potentially reversible causes. The Endocrine Society also cautions that labels such as "functional" and "age-related" can blur the line between treatable disease, normal aging and low testosterone caused by other illness, so the cause still needs to be worked out (JAMA review, 2026; Endocrine Society statement, 2026).

What is late-onset or age-related hypogonadism?

Testosterone often declines with age, but age alone does not diagnose hypogonadism. A large European study found a strictly defined late-onset syndrome in about 2 in 100 men aged 40 to 79 when low testosterone was paired with a specific cluster of sexual symptoms (Wu et al., NEJM 2010). The Endocrine Society said in 2026 that terms such as "age-related" and "late-onset" are hard to define and can blur normal aging with treatable disease (Endocrine Society statement, 2026).

FDA labeling on this group is changing, which we cover in the 2025–2026 section below.

Not sure which type fits your lab results? TRT Provider Guide's Find My TRT Path tool asks a few questions about the tests you've had and your goals. Then it shows which tests you may still be missing and which kind of clinician fits your situation. It's free and educational, and it doesn't diagnose anything. Show me which tests I'm missing →

What causes hypogonadism?

Causes fall into two groups: conditions you're born with, like Klinefelter syndrome or Kallmann syndrome, and things that happen later, like testicle injury, cancer treatment, pituitary disease, severe illness, opioid use or obesity. In adult men, the cause can be structural and permanent or potentially reversible, so a confirmed low testosterone result still needs a cause-focused workup.

Causes you're born with

Klinefelter syndrome. A boy is born with an extra X chromosome (47,XXY). It happens in about 1 in 500 to 1,000 male births, and many men don't find out until adulthood, often during a fertility workup (MedlinePlus).
Undescended testicles that weren't corrected early in childhood.
Kallmann syndrome. The hypothalamus doesn't develop normally. It often comes with a weak or missing sense of smell (Mayo Clinic).
Other rare genetic conditions, such as Noonan syndrome and myotonic dystrophy.

Causes that develop later

Injury to both testicles, or removal of the testicles
Mumps infection of the testicles (orchitis) in the teen or adult years
Chemotherapy or radiation
Iron overload (hemochromatosis)
Pituitary tumors, or pituitary surgery or radiation
High prolactin (a pituitary hormone)
Certain medicines, including opioids, steroid medicines (glucocorticoids) and some prostate cancer drugs
Anabolic steroid use, including the period after stopping
Obesity and metabolic illness, which can lower measured testosterone and sometimes suppress the hormone axis
Sleep disorders, including obstructive sleep apnea, which can affect symptoms and treatment safety and should be assessed when relevant
Long-term kidney or liver disease, and HIV
A serious short-term illness, which can temporarily lower testosterone

Sources: Cleveland Clinic, Mayo Clinic.

Which causes can be reversed?

This is the question most men really want answered. Here's how the common causes tend to sort out. It's general guidance, not a promise about your case.

Table 4: Often temporary or potentially reversible; May improve when the underlying cause can be treated; Often persistent or structural
Often temporary or potentially reversible	May improve when the underlying cause can be treated	Often persistent or structural
Severe short-term illness (testing is usually repeated after recovery)	Obesity-related secondary low testosterone	Klinefelter syndrome
	Opioid or corticosteroid effects, when the medicine can be safely changed by the prescriber	Both testicles removed or severely damaged
	Hyperprolactinemia, depending on its cause	Some testicular damage from chemotherapy or radiation
	Suppression after anabolic-androgenic steroid use; recovery varies and is not guaranteed	Congenital hypothalamic or pituitary disorders may require long-term specialist care

Built by TRT Provider Guide from the 2026 JAMA review of adult male hypogonadism, Cleveland Clinic and Merck Manual Professional.

How strong is the weight link? In the Hypogonadism in Males (HIM) study of more than 2,000 U.S. men aged 45 and up, men with obesity had about 2.4 times the odds of low testosterone. Men with diabetes had about 2.1 times the odds, and men with high blood pressure about 1.8 times (HIM study, PMC). That shows a link, not proof that one causes the other. But it's why a good clinician asks about weight, sleep and medicines before reaching for a prescription pad.

What are the symptoms of hypogonadism?

The most telling symptoms are sexual: low sex drive, fewer morning erections and trouble with erections. Other signs include low energy, low mood, less muscle, more body fat, smaller testicles, breast growth, hot flashes and weaker bones. Many of these are common in men with normal testosterone too, which is why symptoms alone can't diagnose it.

The symptoms that point most clearly to low testosterone

In the European Male Ageing Study, researchers checked dozens of symptoms against testosterone levels. Only three sexual symptoms tracked closely with low testosterone (Wu et al., NEJM 2010, University of Glasgow record):

Fewer morning erections
Less interest in sex
Erectile dysfunction

Six other symptoms showed up more often as testosterone dropped, but they were common in men with normal levels too. Those were trouble with vigorous activity, trouble walking more than a kilometer, trouble bending or kneeling, low energy, sadness and fatigue (ACP Internist).

Signs a doctor can find

Smaller or softer testicles
Less body or facial hair
Breast tissue growth (gynecomastia)
Hot flashes, usually only when testosterone is very low
Low red blood cell count (anemia) with no other explanation
Thinning bones or fractures from minor falls
A low sperm count

Symptoms that are easy to blame on "low T"

Tiredness, brain fog, low mood, weight gain, poor sleep and weaker workouts can all happen with hypogonadism. They also happen with depression, thyroid problems, sleep apnea, stress, alcohol and dozens of medicines. That's why a symptom quiz can tell you testing might be worth it, but it can never tell you that you have hypogonadism.

What does hypogonadism look like?

In adults, often nothing you'd notice in a mirror. When there are visible changes, they include smaller testicles, less facial and body hair, some breast enlargement, more belly fat and less muscle. If hypogonadism starts before puberty, the changes are bigger. Puberty may be delayed or incomplete, the voice may stay high, and arms and legs may grow longer than the trunk (Mayo Clinic).

When to see a doctor in person soon

Some symptoms point to a pituitary problem or another condition that needs more than a testosterone check. Get seen in person if you notice:

New or worsening headaches
Vision changes, especially losing side vision
Milky discharge from the nipples
A lump in a testicle or in the breast

These match the "tumor mass effect" signs that make doctors order pituitary imaging (Endocrine Society criteria, PMC figure). A sudden, severe headache with vision loss needs emergency care now.

How do doctors diagnose hypogonadism?

Doctors diagnose hypogonadism in steps. First come matching symptoms, then a low early-morning testosterone test, then a second low early-morning test on a different day, then tests like LH and prolactin to find the type and cause. Symptoms, a questionnaire or one low result can't make the diagnosis on their own.

Both major U.S. guidelines agree on the recipe. The Endocrine Society says to diagnose hypogonadism only when symptoms fit and testosterone is clearly and consistently low. It recommends a fasting morning total testosterone test from an accurate lab, confirmed by repeating it (Endocrine Society guideline abstract). The AUA says the diagnosis should be made only after two total testosterone tests on separate occasions, both drawn early in the morning (AUA guideline).

The 4 stages of a hypogonadism diagnosis

Stage 1: A reason to test. Usually that's symptoms. But the AUA also suggests checking testosterone in men with certain conditions even without symptoms. These include unexplained anemia, bone loss, diabetes, past chemotherapy or testicular radiation, HIV/AIDS, long-term opioid or steroid use, male infertility and pituitary problems (AUA guideline summary). The Endocrine Society recommends against screening every man for low testosterone (Endocrine Society eGuideline).

Stage 2: The first early-morning test. Testosterone varies with time of day and can also be affected by food intake, sleep and acute illness. Current guidance uses properly timed morning testing, and the Endocrine Society specifies fasting morning samples for confirmation. Testing during an acute illness can give a misleadingly low result. For practical prep, see our guides on the best time of day to test testosterone and how to prepare for a testosterone blood test.

Stage 3: The second early-morning test, on a different day. This is the step people skip, and it's the step that matters most. The Endocrine Society notes that about 30% of men whose first result is in the hypogonadal range have a normal repeat measurement, which is why one low result should not be treated as a diagnosis (Endocrine Society). If two results disagree, a clinician may decide that more testing or a closer look at timing, illness, sleep, medications and assay quality is needed. Our page on whether you need two low testosterone tests goes deeper.

Stage 4: Find the type and the cause. Once low testosterone is confirmed, the next tests answer why:

LH (and often FSH): shows primary vs. secondary. Both major guidelines call for it (Urology Times on AUA; Endocrine Society eGuideline).
Prolactin: checked when LH is low or "normal," especially if testosterone is very low.
Free testosterone: testosterone not bound to proteins in your blood. It's useful when total testosterone is near the cutoff, or when you have a condition that changes a protein called SHBG (sex hormone-binding globulin), which carries testosterone in your blood (Endocrine Society guideline abstract).
Pituitary MRI: considered when testosterone is very low (under about 150 ng/dL) with low or normal LH, when prolactin stays high, or when there are headaches or vision changes (CCJM review of Endocrine Society guidance).
Other tests as needed: iron studies, a chromosome test (karyotype) for Klinefelter syndrome, and a semen analysis if fertility matters.

For the full list of labs most clinicians want before treatment, see what blood tests are required before TRT.

How to read the hormone pattern

Table 5: Testosterone (confirmed low); LH / FSH; What it usually points to; What it can mean for fertility; Typical next step
Testosterone (confirmed low)	LH / FSH	What it usually points to	What it can mean for fertility	Typical next step
Low	High	Primary hypogonadism (testicles)	Sperm production may be impaired. Fertility treatment depends on the cause and remaining testicular function.	Look for the cause (for example, genetic disease, injury, past chemotherapy or radiation). Fertility-focused care first if you want kids.
Low	Low or "normal"	Secondary hypogonadism (brain signal)	Depending on the cause, gonadotropin therapy can sometimes stimulate sperm production. Exogenous testosterone suppresses spermatogenesis.	Prolactin and medication review; assess obesity, severe illness and other contributors. MRI is considered in selected patients, including very low testosterone with low/normal LH or pituitary red flags.
Low	Mixed signals	Mixed hypogonadism	Varies	Specialist evaluation
Only one low result	Not tested yet	Not diagnosed yet	Unknown	Repeat the early-morning test and add LH

Built by TRT Provider Guide from Merck Manual Professional, the Endocrine Society eGuideline and the CCJM review. This explains common patterns. It can't interpret your personal results.

Can a home or finger-prick test diagnose hypogonadism?

Not by itself. The guidelines above are built around a blood draw from a vein, done early in the morning at a reliable lab, and then repeated. A home kit can be a first signal that something's worth checking. Before you rely on one, ask three questions. Is it a finger-prick or a vein draw? Which lab runs it? Will the plan include a confirming early-morning test before anyone talks about treatment?

What's the ICD-10 code for hypogonadism?

If you saw a code on a lab order or an insurance form, these are the common ones in the ICD-10-CM system U.S. doctors use for billing:

Table 6: Code; What it covers
Code	What it covers
E29.1	Testicular hypofunction; the ICD-10-CM tabular list includes testicular hypogonadism NOS here
E23.0	Hypopituitarism; the ICD-10-CM tabular list also points isolated gonadotropin deficiency to this code
E89.5	Postprocedural testicular hypofunction
Q98.x	Klinefelter syndrome code family

Source: CDC ICD-10-CM files, current for services beginning October 1, 2026. A code on a lab order or claim is a billing/classification code; it does not by itself prove that a diagnosis has been clinically confirmed.

Have one testosterone number and no plan? Find My TRT Path turns where you are into a short checklist. You'll get which test to repeat, what to add (like LH) and what to ask your doctor at the next visit. Build my lab checklist →

Is 300 ng/dL the definition of hypogonadism?

No single testosterone number diagnoses hypogonadism by itself. U.S. guidance commonly uses a threshold near 300 ng/dL, while exact lower limits vary by guideline, assay and reference range. The diagnosis still requires compatible symptoms or signs plus consistently low, accurately measured morning testosterone, so the number is only one piece of the diagnosis.

Here's how the major authorities define it, side by side. To get this view yourself, you'd have to open six documents, several of them long clinical PDFs.

The Hypogonadism Definition Ledger

Table 7: Authority; What they call it; Testosterone line; Testing rule; Symptoms required?
Authority	What they call it	Testosterone line	Testing rule	Symptoms required?
American Urological Association (guideline 2018, validity confirmed 2024)	Testosterone deficiency	Total testosterone below 300 ng/dL as a reasonable cutoff	Two tests on separate days, both early morning	Yes
Endocrine Society (2018 guideline)	Hypogonadism	Lower limit of about 264 ng/dL (9.2 nmol/L) for healthy, non-obese young men on certified lab tests	Clearly and consistently low on repeat fasting morning tests	Yes
European Association of Urology (2026 guideline)	Male hypogonadism / late-onset hypogonadism	Uses 12 nmol/L (about 346 ng/dL) as its total-testosterone threshold for late-onset hypogonadism when symptoms are present	Morning fasting measurement; repeat on at least two occasions when below 12 nmol/L	Yes
FDA (testosterone product approvals)	Primary hypogonadism and hypogonadotropic hypogonadism	No single number	Per product label	Approved for men with low testosterone plus an associated medical condition
European Male Ageing Study (research definition, 2010)	Late-onset hypogonadism	Below 11 nmol/L (about 320 ng/dL) plus low free testosterone	One study visit	Three sexual symptoms required
ICD-10-CM (billing codes)	Testicular hypofunction (E29.1) and related codes	None	None	None. It's a coding system, not a diagnostic standard.

Built by TRT Provider Guide, October 2026, from the AUA guideline, Endocrine Society guideline (PubMed) with its harmonized range per MDedge coverage, the EAU 2026 Male Hypogonadism guideline, the FDA testosterone information page, Wu et al. (University of Glasgow record) and the ICD-10-CM E29.1 entry.

What this table shows: major authorities agree that a testosterone number cannot be interpreted by itself, even though they use somewhat different thresholds and reference ranges. The common core is compatible symptoms or signs plus consistently low, properly measured morning testosterone. If someone tells you one number settles the diagnosis, they're skipping the clinical context.

Why do the numbers differ? Labs use different testing methods. Guidelines were written from different groups of men. And total testosterone gets harder to read when SHBG is high or low. For the full number debate, including what to do with a "borderline" result, see what testosterone level qualifies for TRT.

How common is hypogonadism?

It depends on what is being counted. An older U.S. study found that about 39% of men age 45 and older had one total-testosterone result below 300 ng/dL, but that is biochemical low testosterone, not the same thing as a confirmed diagnosis. Studies that require symptoms plus low hormone levels produce much lower estimates.

You'll see wildly different numbers quoted for how many men have hypogonadism. They're not contradicting each other. They're measuring different things. Line them up and the pattern jumps out:

The "low testosterone vs. clinical hypogonadism" prevalence ladder

Table 8: Study; Who was tested; How "hypogonadism" was defined; Share who qualified
Study	Who was tested	How "hypogonadism" was defined	Share who qualified
HIM study (2006)	2,162 U.S. men aged 45+ at primary-care visits	One total testosterone result under 300 ng/dL. Symptoms not required.	38.7%
BACH survey (2007)	1,475 randomly chosen Boston-area men aged 30–79	Low total testosterone alone	24%
BACH survey (2007)	Same men	Low total and free testosterone plus symptoms	5.6%
European Male Ageing Study (2010)	About 3,000 European men aged 40–79	Low total and free testosterone plus three sexual symptoms	2.1%

Built by TRT Provider Guide from the HIM study, BACH survey coverage in Healio and ScienceDaily, and EMAS results per ACP Internist and PubMed 22419720.

These studies are not a single stepwise experiment, so their percentages should not be compared as if one cohort was repeatedly filtered. What they do show is that prevalence depends heavily on the definition: one low total-testosterone measurement produces a much higher number than definitions that also require symptoms and more specific biochemical criteria.

Age matters too. In the BACH survey, symptomatic low testosterone rose to 18.4% in men 70 and older (ScienceDaily). In the European study, strict late-onset hypogonadism went from about 0.1% of men in their 40s to about 5% of men in their 70s (TIME Healthland; Canadian Journal of Urology).

So when you see a claim that roughly 4 in 10 older men have "low T," check what was actually measured. That figure can come from a single testosterone result, while much lower figures come from studies that required symptoms plus stricter biochemical criteria. Those are different questions, not competing answers to the same definition.

Is hypogonadism dangerous?

Hypogonadism is rarely an emergency. But long-term low testosterone that isn't addressed is linked with weaker bones, anemia, less muscle, sexual problems and infertility. Sometimes the cause is the bigger concern, like a pituitary tumor or iron overload, which is why finding the cause matters as much as the testosterone number.

Long-term effects

Over time, untreated hypogonadism can lead to:

Bone thinning (osteoporosis) and fractures from minor falls
A low red blood cell count (anemia)
Loss of muscle mass and strength
Ongoing low sex drive and erection problems
Infertility

Sources: Mayo Clinic, Cleveland Clinic.

When the cause is the real issue

A low testosterone result can be the first clue to something else, such as a pituitary tumor, high prolactin, iron overload or a testicular problem. That's why the LH and prolactin step in the diagnosis isn't optional busywork. It's how those causes get caught.

Does hypogonadism shorten your life?

There's a link, but not proof that low testosterone causes early death. In a follow-up of the European Male Ageing Study, men with testosterone under 8 nmol/L (about 230 ng/dL) had roughly twice the risk of dying during the study. Men with all three sexual symptoms had about three times the risk, regardless of their testosterone level (Pye et al., JCEM 2014). Low testosterone may partly be a marker of poor overall health. That study doesn't show that treating it would change the risk.

Does hypogonadism always mean you need testosterone therapy?

No. Treatment depends on whether the diagnosis is confirmed, why testosterone is low, whether the cause might be reversible, your health risks and whether you want children. Testosterone replacement therapy is one treatment for confirmed hypogonadism, but finding and treating the cause comes first, and some men are better served by other options.

We'll be straight with you, even though we're a site about TRT. TRT Provider Guide does not treat a hypogonadism diagnosis as a ticket to testosterone. At this stage, the useful question is whether the diagnosis is solid, what is causing the low level, and whether fertility or another health issue changes the care route. Provider comparison belongs later, after those questions are answered.

Treating the cause first

When a potentially reversible cause is lowering testosterone, treating that cause can come before testosterone therapy. A 2026 JAMA review identifies obesity, severe illness and certain medicines as common potentially reversible causes of secondary hypogonadism; for obesity-induced hypogonadism, weight loss is recommended as first-line management (JAMA review, 2026). Sleep apnea should also be assessed when relevant because untreated severe obstructive sleep apnea affects treatment decisions. Never stop a prescribed medicine on your own. Talk to the prescriber first.

Three kinds of treatment, kept separate

People often lump these together. They're not the same, and the differences matter for safety, cost and fertility.

Table 9: Category; Examples; FDA status; What to know
Category	Examples	FDA status	What to know
FDA-approved testosterone	FDA-approved products include gels, patches, buccal systems and injections; additional approved products use other delivery forms	FDA's current testosterone information page says approved products are for men with low testosterone plus an associated medical condition	Testosterone is Schedule III and requires a valid prescription. Exogenous testosterone suppresses spermatogenesis. FDA labeling was updated in 2025 for blood-pressure and cardiovascular-safety information, with additional label changes requested in June 2026.
Compounded testosterone	Custom creams or injections made by a compounding pharmacy	Not FDA-approved	Compounded drugs aren't reviewed by the FDA for safety, effectiveness or quality the way approved products are. AUA guidance favors commercially made products over compounded ones when possible.
Treatments that aren't testosterone	hCG, clomiphene, enclomiphene	hCG products such as Pregnyl are FDA-approved for selected cases of hypogonadotropic hypogonadism in males. Clomiphene is FDA-approved for ovulatory dysfunction in women and is used off-label in men. Enclomiphene is not FDA-approved as a drug product.	These are not TRT. Their role depends on the cause of hypogonadism and fertility goals. hCG can stimulate the testes in selected secondary hypogonadism; clomiphene use in men is off-label, and enclomiphene lacks FDA drug approval.

Sources: FDA testosterone information, FDA class-wide labeling changes, FDA on compounding, Pregnyl labeling on DailyMed, clomiphene labeling on DailyMed, Merck Manual Professional, and FDA advisory committee materials on enclomiphene (FDA PCAC materials).

Who usually shouldn't start testosterone yet

The Endocrine Society recommends against starting testosterone in men who:

plan to have children in the near term,
have breast or prostate cancer,
have a prostate lump or a PSA above 4 ng/mL (or above 3 ng/mL in higher-risk men) without a urology evaluation first,
have a high hematocrit (the share of your blood made of red blood cells),
have untreated severe sleep apnea or severe urinary symptoms,
have uncontrolled heart failure,
had a heart attack or stroke in the last 6 months,
or have a blood-clotting disorder.

Source: Endocrine Society guideline abstract. PSA (prostate-specific antigen) is a blood test used to screen for prostate problems.

In June 2026, FDA requested updates to testosterone prescribing information, including revised safety information related to prostate cancer and benign prostatic hyperplasia. That request does not erase the Endocrine Society's clinical contraindications or turn a label proposal into an individualized treatment decision (FDA testosterone information).

If TRT does become part of the plan, it comes with regular monitoring. See how often you need bloodwork on TRT, does TRT work and how long TRT takes to work.

Can hypogonadism affect fertility?

Yes. Hypogonadism can reduce sperm production, and exogenous testosterone can suppress it further by lowering the brain and pituitary signals that support spermatogenesis. If you want children in the near term, get a fertility-focused evaluation before starting testosterone.

This is the section we most want you to read before any treatment decision. Here's the problem in one line: testosterone from outside your body tells your brain to turn off LH and FSH, and FSH is what keeps sperm production going. So your testosterone level can look great while your sperm count drops.

What the guidelines say:

The AUA says men with testosterone deficiency who are interested in fertility should have a reproductive health evaluation before treatment (AUA guideline).
The Endocrine Society recommends against starting testosterone in men planning fertility in the near term (Endocrine Society guideline abstract).
In secondary hypogonadism, gonadotropin therapy can restore sperm production in some men when the testes are capable of responding. In primary hypogonadism, fertility treatment depends on the specific testicular disorder and remaining function, so reproductive-urology evaluation is important (Merck Manual Professional).

Nobody can promise you'll stay fertile or get fertility back on a set timeline. Outcomes depend on the cause, your age and how long the problem has been going on. That uncertainty is exactly why the fertility conversation comes first.

Which path fits your plans?

Table 10: Do you want biological children in the next few years?; Your best next move
Do you want biological children in the next few years?	Your best next move
Yes	Fertility-focused evaluation before any testosterone. Start with a urologist, a reproductive urologist (male fertility specialist) or an endocrinologist.
Maybe	Treat fertility as an unresolved priority. Ask whether semen analysis or fertility-focused counseling belongs before treatment.
No	Fertility may be less central to the immediate decision, but tell your clinician about your reproductive goals because exogenous testosterone can suppress sperm production.

If kids are on your list, your path looks different from the typical TRT path. Find My TRT Path flags fertility-first care routes and gives you the exact questions to ask a urologist before you agree to any testosterone. Map my fertility-first path →

What changed for hypogonadism treatment in 2025 and 2026?

In 2025 the FDA removed boxed-warning language about increased cardiovascular risk from testosterone labels and required blood-pressure information. In June 2026 it requested additional label updates, including removal of the age-related-hypogonadism limitation of use. Federal telemedicine flexibilities that can allow controlled-substance prescribing without a prior in-person exam remain in effect through December 31, 2026 when all federal conditions and applicable state law are met.

If you read about hypogonadism before 2025, some of it is now out of date. Here's what changed, in order:

Table 11: Date; What happened; What it means for you
Date	What happened	What it means for you
Feb 28, 2025	FDA ordered class-wide label changes. It added the TRAVERSE heart-safety trial results, removed boxed-warning language about higher cardiovascular risk, and required blood pressure warnings.	The heart attack and stroke boxed language came off. Blood pressure checks matter more than before.
Dec 2025	FDA convened an expert discussion on testosterone therapy in men, including whether evidence supported broader labeled use.	Discussion only. It did not change testosterone's Schedule III status or product indications by itself.
Jan 1, 2026	DEA and HHS extended the COVID-era controlled-substance telemedicine flexibilities through Dec 31, 2026.	A DEA-registered practitioner may prescribe Schedule II-V controlled substances by qualifying telemedicine without a prior in-person exam if all federal conditions are met; state law and professional-licensing rules still apply.
Apr 20, 2026	FDA Federal Register notice on testosterone for low libido in men with hypogonadism that has no clear cause	Signals possible future changes to approved uses
Jun 2026	FDA requested label updates: remove the age-related hypogonadism "limitation of use" and revise information on prostate cancer and benign prostatic hyperplasia.	This was a requested labeling change. FDA's current testosterone information page still says approved products are for men with low testosterone plus an associated medical condition, so check the current label for the specific product.
Jul and Sep 2026	Insurance drug policies we checked (an Aetna Better Health Medicaid policy effective July 16, 2026, and a CVS Caremark criteria document posted in September 2026) still list the old age-related limitation.	Your insurer's paperwork may lag behind the FDA.
Aug 25, 2026	DEA's final-rule package for Special Registrations for Telemedicine entered White House regulatory review. It remained pending as of October 2, 2026.	The temporary 2026 flexibilities remain the operative federal bridge while the permanent rule is still under review.

Sources: FDA labeling changes (Feb 2025), Epocrates summary, Healio on the FDA panel, Holland & Knight on the DEA extension, Federal Register 2026-07615, FDA testosterone information (content current as of June 23, 2026), Aetna Better Health policy, CVS Caremark criteria (via NHPRI), McDermott Will & Schulte (Sept. 18, 2026).

One detail worth knowing from the heart-safety trial: in TRAVERSE, which followed more than 5,200 men, 7.0% of men on testosterone gel had a major heart event, compared with 7.3% on placebo. The FDA found no new safety signal (FDA).

Does this mean age-related low T is now "approved"?

No blanket approval follows from the June 2026 request. FDA asked sponsors to remove the age-related-hypogonadism limitation of use, but FDA's current testosterone information page still states that approved testosterone products are for men with low testosterone plus an associated medical condition. Product labels can update on different schedules, and the diagnostic standard still requires symptoms or signs plus consistently low testosterone on repeat morning testing.

Can you get diagnosed and treated online?

Often, but only when the clinician and encounter meet federal and state requirements. Testosterone is a Schedule III controlled substance under federal law (DEA drug scheduling). Through December 31, 2026, a DEA-registered practitioner may prescribe Schedule II-V controlled substances by qualifying telemedicine without a prior in-person exam if the federal rule's conditions are met; state law, licensure rules and provider policies can still be stricter (HHS/DEA extension).

Before you sign up anywhere, ask these four questions:

Do you require two early-morning blood tests before prescribing?
Do you check LH to find out what's causing low testosterone?
Is the testosterone FDA-approved or compounded?
How do you handle fertility if I might want kids?

What should you do next?

Your next step depends on where you are: no tests yet, one low test, two confirmed low tests, or a known cause. Find your row below. If you're still unsure, use a free decision tool to map your care route before you pay anyone.

Table 12: Your situation; Best next step; Who to see
Your situation	Best next step	Who to see
Symptoms, no testosterone test yet	Ask a clinician whether properly timed testosterone testing is appropriate	Primary care
One low result	Confirm with another properly timed morning test; the clinician may add LH/FSH based on the situation	Primary care, or whoever ordered the first test
Two low results with matching symptoms/signs, cause not evaluated	Cause-focused testing such as LH/FSH, with prolactin or other tests when indicated	Primary care or endocrinology
Confirmed, and you want kids soon	Fertility-focused evaluation before exogenous testosterone	Urology, reproductive urology or endocrinology
Confirmed, with very low testosterone, persistent high prolactin, severe headaches or vision changes	Pituitary-focused evaluation	Endocrinology; urgent or emergency care for acute neurologic symptoms
Confirmed, with a potentially reversible contributor such as obesity, severe illness or a causative medicine	Address the contributor when possible and reassess with the treating clinician	Primary care or relevant specialist
Confirmed, no fertility plans, no red flags	Discuss treatment options and monitoring, then compare appropriate care models	Primary care, urology, endocrinology or a qualified telehealth clinic, depending on the cause and state rules
Teen with delayed puberty	Pediatric evaluation	Pediatrician or pediatric endocrinologist
A woman with symptoms of low hormones	Women's health evaluation	Primary care, gynecology or endocrinology

The right TRT provider is not the same for every person — it depends on whether low testosterone has been properly evaluated, your symptoms and health history, your fertility plans, your state, your insurance or cash-pay preference, your treatment-format preference, your budget, and whether online or in-person care is the better starting point. Some situations belong with primary care, urology, endocrinology, reproductive urology, or urgent or emergency care when the symptoms warrant it. Because a general answer cannot resolve those for you, use TRT Provider Guide's Find My TRT Path tool to map your situation to the right care route and the questions to ask before you pay.

Get your personalized next-step plan. Answer a few questions about your tests, symptoms and fertility plans. Find My TRT Path shows where you are in the process, which tests may be missing, which type of clinician fits and what to ask before you pay anyone. It's free and educational. It doesn't diagnose low testosterone, decide whether you qualify for treatment or guarantee a prescription. Map the care route that fits me →

Hypogonadism FAQ

Quick, direct answers to the questions men ask most after learning what hypogonadism is.

Is hypogonadism the same as low T?

Not quite. Low T is a lab result. Hypogonadism is a diagnosis that needs matching symptoms plus testosterone that's low on two separate early-morning tests.

What is the difference between primary and secondary hypogonadism?

Primary hypogonadism starts in the testicles, and LH runs high. Secondary hypogonadism starts in the brain's signals, and LH is low or oddly normal.

What is hypogonadotropic hypogonadism?

It's another name for secondary hypogonadism. "Hypogonadotropic" means the brain's signal hormones (LH and FSH) are too low to drive the testicles.

What testosterone level is considered hypogonadism?

No testosterone level diagnoses hypogonadism by itself. U.S. guidance commonly uses thresholds near 300 ng/dL, but the exact lower limit depends on the guideline, assay and reference range; compatible symptoms or signs and repeat morning testing are still required.

Can you have hypogonadism with a total testosterone result that is not clearly low?

Sometimes the total-testosterone result can be misleading when SHBG is unusually high or low. Guidelines recommend considering accurately measured or calculated free testosterone in selected cases, such as when total testosterone is near the lower limit or a condition that alters SHBG is present.

Can you have one low testosterone result without hypogonadism?

Yes. About 30% of men whose first result is low test normal on the retest. Illness, poor sleep and testing later in the day can all pull a single result down.

Can hypogonadism be cured?

Some causes can improve, especially severe illness, obesity-related secondary low testosterone and medicine-related suppression when the underlying problem can be safely corrected. Structural or genetic causes such as Klinefelter syndrome or loss of both testicles are generally persistent and need long-term specialist management.

Is hypogonadism genetic?

Some causes are, like Klinefelter syndrome and Kallmann syndrome. Many aren't. Weight, medicines, injury and illness cause a large share of cases.

Can young men have hypogonadism?

Yes. Age isn't required. In younger men, causes more often include genetic conditions, injury, cancer treatment, opioids or anabolic steroid use.

Can steroid use cause hypogonadism?

Yes. Anabolic steroids can shut down your body's own testosterone production, and low levels can last after stopping. See a clinician rather than trying to manage it yourself.

Does hypogonadism cause erectile dysfunction?

It can contribute. Low sex drive and fewer morning erections are more specific signs of low testosterone. Erectile dysfunction has many other causes, especially blood vessel and nerve problems.

What's the ICD-10 code for hypogonadism?

E29.1 (testicular hypofunction) is the most common. E23.0 is often used for secondary hypogonadism caused by the pituitary, and E89.5 for hypogonadism after surgery or radiation.

Does insurance cover hypogonadism treatment?

Coverage varies by plan, product and diagnosis. Many plans require documentation such as symptoms, repeat low morning testosterone results and a covered diagnosis, but the exact laboratory threshold, prior-authorization rules and exclusions differ, so check the current criteria for your own plan.

What doctor treats hypogonadism?

Primary care can start the workup. Endocrinologists handle pituitary and complex cases. Urologists and reproductive urologists handle testicular problems and fertility.

How we made this page

Who: The TRT Provider Guide Editorial Team wrote and fact-checked this page against the primary and high-authority sources listed below. It has not been reviewed by a clinician.

How: We checked current Endocrine Society guidance and its 2026 statement, the AUA's still-current 2018 guideline (validity confirmed 2024), the 2026 JAMA review of adult male hypogonadism, FDA testosterone information and labeling notices, DEA/HHS telemedicine rules, current ICD-10-CM files and the prevalence studies used below. From those we built the Stage Map, Definition Ledger, hormone-pattern table and Prevalence Ladder. Our general approach to evidence follows How We Review TRT Providers, which separates verified facts, provider-stated claims, customer-experience signals and our own editorial conclusions.

Why: Most pages define the word. We wanted one page that also shows you where you are in the diagnosis and what to do next, before anyone asks you to pay for treatment.

What we actually verified (October 2, 2026)

Confirmed from primary or high-authority sources:

Diagnosis requires symptoms or signs plus consistently low testosterone on repeat fasting morning tests (Endocrine Society). The AUA requires two early-morning tests on separate days and uses a cutoff below 300 ng/dL.
About 30% of men with a first low result test normal on repeat (Endocrine Society).
LH and FSH separate primary from secondary hypogonadism (Endocrine Society, Merck Manual Professional).
Fertility evaluation belongs before treatment (AUA). Starting testosterone is not recommended for men planning fertility soon (Endocrine Society).
FDA's current testosterone information page says approved testosterone products are for men with low testosterone plus an associated medical condition. FDA requested additional label updates in June 2026, including removal of the age-related-hypogonadism limitation of use.
Federal controlled-substance telemedicine flexibilities run through December 31, 2026 when the rule's conditions are met. DEA's Special Registration final-rule package entered White House regulatory review on August 25, 2026 and remained pending on October 2, 2026.
Testosterone remains a Schedule III controlled substance under federal law.

What we did not confirm: We did not check every individual testosterone product label for implementation of the June 2026 requested changes, and we did not attempt a 50-state telemedicine-law survey for this definitional page. Product labels update individually, and state prescribing or in-person requirements can differ from the federal temporary rule.

Still not sure which TRT care route fits you? Use our free Find My TRT Path tool. Find My TRT Path →

This page is educational information, not medical advice. It can't diagnose hypogonadism or interpret your lab results. If you have a sudden severe headache, vision loss or other urgent symptoms, get urgent or emergency care.