When is a blood test recommended for low testosterone?

Low testosterone can be associated with reduced sexual desire, erection difficulties, low energy, reduced muscle strength, mood changes, or difficulty fathering a child. These symptoms have other possible explanations, so a result is interpreted alongside your medical history and examination.

Testosterone changes during the day and can be affected by illness, poor sleep, some medicines, and changes in weight. A clinician may request an early-morning sample and may repeat an unexpectedly low result before discussing treatment. Other hormone tests can help identify whether the testicles or the brain’s hormone signals are involved.

Tell the clinician about symptoms, medicines, supplements, sleep problems, recent illness, and any plans for fertility. Follow the instructions about fasting or morning collection if provided. Do not start testosterone or stop prescribed medicine because of a single result; discuss the finding and the next test, if needed.

Arrange a routine appointment for persistent symptoms, sexual changes, unexplained tiredness, or concerns about fertility. Seek urgent care for sudden severe headache, vision loss, fainting, chest pain, or severe breathlessness, because these symptoms need assessment beyond a testosterone test.

Which symptoms make testing useful for me? Should the sample be collected in the morning or repeated? Could my medicines, sleep, or recent illness affect the result? Which other tests might explain these symptoms?