What causes low testosterone in men

Low testosterone causes in men range from a gradual age-related decline to treatable health conditions, medicines, and problems involving the testes or pituitary gland. Excess body fat and some chronic illnesses can lower measured levels, while injury, chemotherapy, and certain drugs can interfere with hormone production. A symptom alone cannot identify the cause: diagnosis requires compatible symptoms and two consistently low early-morning blood tests, followed by evaluation to find out why.

Common reasons testosterone may be low

Testosterone is made mainly in the testes under signals from the hypothalamus and pituitary gland. Testicular problems can reduce production directly; disrupted brain signals may leave the testes without enough stimulation. Clinicians distinguish these patterns with blood tests, including luteinizing hormone and follicle-stimulating hormone.

Cause group	Examples	What may be going on
Testicular causes	Injury, infection, surgery, chemotherapy, some genetic conditions	The testes may be unable to make enough testosterone despite normal or increased signaling from the brain.
Brain or pituitary causes	Pituitary disease, significant head injury, some tumors or treatments	The signals that normally prompt testosterone production may be reduced.
Health and metabolic factors	Obesity, type 2 diabetes, severe illness, some sleep disorders	These can be associated with lower levels, sometimes temporarily or as part of a wider health issue.
Medicines and substances	Long-term opioids, glucocorticoids, chronic heavy alcohol use, anabolic steroid withdrawal	Some can interfere with hormone signaling or production.

These examples are not a way to diagnose yourself. An abnormal result needs interpretation with symptoms, medical history, examination, and repeat testing.

Aging and ordinary variation

Testosterone tends to decline with age, but age alone does not establish testosterone deficiency. In a study of middle-aged men, age and body mass index were associated with lower testosterone measures, while marked total testosterone reductions were uncommon; the relationship with diabetes was no longer significant after accounting for age and body mass index. That study was cross-sectional, so it describes associations rather than proving one factor caused a change in an individual man. (PMID 24115523)

Levels vary with time of day, recent illness, and laboratory method. A single low reading, especially during temporary illness, may not represent a lasting problem. A clinician may repeat an unexpectedly low test under appropriate morning conditions.

For more context, see what testosterone does in a man’s body and normal testosterone levels by age.

Excess body fat and metabolic health

Among common low testosterone reasons, excess body fat is one of the better studied. In the study above, body mass index was independently associated with lower total testosterone. This does not mean every man with a larger waist has low testosterone or that weight explains every low test. Diabetes, medicines, sleep problems, and other illnesses can overlap. (PMID 24115523)

Weight and testosterone can also influence each other. A low result should not become a reason for shame or an assumption that weight is the only cause. If excess weight or diabetes is part of your health picture, your clinician can help address those concerns and decide whether hormone testing is appropriate. Read more about low testosterone and weight gain.

Problems affecting the testes or pituitary

Testicular injury, surgery, chemotherapy or radiation, some infections, and inherited conditions can affect testosterone production. In other cases, pituitary or hypothalamus problems disrupt signals to otherwise capable testes. These examples belong in a medical history, not self-diagnosis.

When repeat testing confirms low testosterone, a clinician may check related hormones and investigate the cause based on the results and history. A suddenly changing symptom pattern deserves attention, especially when it occurs alongside headaches or vision changes. The Endocrine Society guideline advises confirming consistently low morning testosterone in men with compatible symptoms and then evaluating the cause.

Medicines and substances sometimes called “testosterone killers”

The phrase testosterone killers is an online shorthand, not a medical diagnosis. Some medicines can affect hormone production or regulation. Long-term opioid exposure is one example clinicians may consider. A systematic review and meta-analysis found that opioid use was associated with testosterone suppression, though effects can differ with the drug, duration, and individual health circumstances. (PMID 25702934)

Chronic alcohol consumption has also been studied. A meta-analysis of controlled trials found lower average total and free testosterone in healthy men exposed to chronic alcohol consumption, but the findings did not apply in the same way to acute alcohol intake or participants with a recognized alcohol use disorder. The paper describes a group-level association, not a prediction about any one drinker. (PMID 37705506)

Do not stop a prescribed medicine or change its dose on your own. If you use opioids, glucocorticoids, or other medicines and have symptoms that concern you, ask the prescriber whether the medication could be relevant. More about alcohol and hormones is in alcohol and testosterone.

Can testosterone levels drop suddenly?

They can fall for a time during significant illness, after an injury or medical treatment, or when a medicine or substance affects hormone signaling. A result may also reflect normal variation or testing conditions. A lasting unexplained change or abrupt symptoms call for assessment, not an assumption that testosterone has permanently fallen.

The sleep connection is often oversimplified. A randomized study tested acute and longer-term sleep restriction in small groups of healthy young men and found no adverse effect on testosterone overall; its authors said further studies were needed across men’s ages. It cannot answer every question about older men or sleep disorders, but it cautions against claiming that short sleep alone always causes low testosterone. (PMID 31416797) If loud snoring, breathing pauses, or severe daytime sleepiness are present, mention them to a clinician. See sleep and testosterone.

Warning signs that need medical care

Make an appointment if you have persistent loss of sexual interest, fewer spontaneous erections, unexplained loss of strength or muscle, infertility concerns, or other ongoing changes that affect daily life. These symptoms have many possible causes and do not prove testosterone is low. Low testosterone symptoms in men over 50 explains what to notice and what testing can clarify.

Seek prompt medical care for a testicular lump, a breast lump or swelling, sudden loss of libido with headaches or vision change, chest pain with sexual activity, or an erection lasting more than four hours. New or worsening symptoms deserve medical care. If low mood includes thoughts of self-harm, call or text 988 in the United States for the Suicide and Crisis Lifeline, or seek emergency help if there is immediate danger.

Habits to address before supplements

Habits support overall health and may address contributors such as excess weight or alcohol. They do not replace evaluation for persistent symptoms.

• Work toward sustainable weight and metabolic health. If excess weight or diabetes applies, discuss a realistic plan with a health professional. Research links higher body mass index with lower testosterone, but the relationship is not simple and weight loss is not a guaranteed hormone fix. (PMID 24115523)
• Build regular activity into the week. Walking, strength work appropriate to your ability, and less sitting can support cardiovascular and metabolic health. Choose a pace you can maintain, and ask for guidance if you have symptoms or medical limits.
• Keep a steady sleep routine and report possible sleep apnea. Good sleep supports general health. The available sleep-restriction trial does not show that improving sleep will necessarily raise testosterone, but persistent sleep problems deserve attention for their own sake. (PMID 31416797)
• Be candid about alcohol and medicines. Share how much you drink and the names of prescriptions, pain medicines, and supplements you use. Chronic alcohol and long-term opioids may be relevant; your clinician can help weigh that evidence in context. (PMID 37705506; PMID 25702934)
• Avoid unsupervised hormone or bodybuilding products. Products marketed to change hormones can complicate testing and create health risks. Tell your clinician what you have taken, including products you may consider ordinary supplements.

What about supplements?

Supplements are not a substitute for finding the cause of persistently low testosterone. Evidence varies by ingredient and product, and a supplement should not be presented as a way to diagnose or treat testosterone deficiency. Our male vitality supplement comparison uses strict scores; the ratings are cautious, and results vary. If you are comparing labels, ErecPrime is the highest-rated male vitality review in this category, with a modest score. Talk to your doctor before using supplements, especially with medications, because ingredients can interact or affect testing.

Next step

If symptoms have lasted or are worsening, the most useful next step is to learn how proper testing works: read testosterone blood test: timing, results and what to ask and discuss your history with your doctor.

FAQ

What is the most common cause of low testosterone in men?

There is no single cause for every man. Age, excess body fat, chronic health conditions, medicines, and problems involving the testes or pituitary can all matter. Testing and medical history help sort them out.

Can stress cause low testosterone?

Stress may affect sleep, mood, sexual function, and general health, but it cannot establish the cause of a low testosterone result. Persistent symptoms deserve a clinical assessment.

Can testosterone levels drop suddenly?

A temporary drop can occur around significant illness, injury, treatment, or a medicine effect. A sudden change in symptoms should be discussed with a clinician, especially with headaches or vision changes.

Does low testosterone always mean I need treatment?

No. Symptoms and consistently low morning test results need to be considered together, and the cause should be evaluated. A clinician can discuss appropriate options and their benefits and risks.

Should I take a testosterone booster?

Do not use a booster to self-diagnose or replace medical evaluation. Product evidence and quality vary. Talk to your doctor before taking one, especially if you use medication.

Reminder: Results vary. Talk to your doctor, especially with medications. New or worsening symptoms deserve medical care.