What to know about low testosterone in men

Testosterone is made mainly in the testicles and supports sexual desire, erections, sperm production, bone health, red blood cell production and muscle maintenance. Low testosterone, also called testosterone deficiency or hypogonadism, may develop when the testicles do not make enough hormone or when the brain signals controlling them are disrupted.

Possible clues include reduced sex drive, fewer spontaneous erections, erectile difficulty, tiredness, reduced strength, loss of muscle, low mood, difficulty concentrating or reduced body hair. These symptoms can also arise from poor sleep, stress, depression, some medicines, obesity or another illness, so symptoms alone do not establish the diagnosis.

Arrange an appointment if symptoms persist or affect relationships, work or wellbeing. A clinician may ask about medicines, sleep, mood, fertility plans and other health conditions, examine you and request blood tests. Testosterone is commonly checked in the morning and may need repeat testing because levels vary. Further tests can help identify whether the problem is coming from the testicles or the hormone-control centres in the brain.

Treatment depends on the cause and your goals. Improving sleep, managing weight, limiting excess alcohol, reviewing medicines and treating related illness may help. Testosterone replacement is not suitable for everyone, especially when fertility is a current goal, because it can reduce sperm production. Do not start hormone products bought without medical supervision.

Book routine medical care for ongoing changes in libido, erections, energy, mood or strength. Seek prompt care for sudden severe testicular pain, a new testicular lump, marked breast enlargement, severe headache with vision changes or symptoms that begin soon after using an unprescribed hormone product. Urgent help is also appropriate for thoughts of self-harm or severe emotional distress.

Ask: Could another condition or medicine explain these symptoms? Which tests are needed, and should testing be repeated in the morning? How might treatment affect fertility, prostate monitoring or existing health problems? What changes should I track, and when should we review the plan?