Testosterone deficiency

Also called hypogonadism

Key points about testosterone deficiency

  • Testosterone deficiency is the name given to low testosterone levels in men.
  • It can be caused by many things, including injury, infection, medication and chronic health conditions.
  • It can lead to loss of morning erections, decreased libido, erectile dysfunction, breast growth, infertility and decreased energy.
  • Testosterone replacement therapy (also known as TRT)  can improve your mood, energy, wellbeing, libido and sexual function if you have a low testosterone level.
  • A low testosterone level by itself doesn't need treatment. 
  • TRT can have side effects, 
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Low testosterone can be due to problems within your testicles and/or from problems in the rest of your body. Sometimes the cause is unknown.

If your doctor discovers that you have low testosterone, the first step is confirming it with a second test. Further tests are then needed to work out the cause of the low testosterone. Testosterone levels should be tested in the morning before 9 am. 

Some of the causes of low testosterone in men include:

  • injury to your testicles (trauma, castration) or infection
  • radiation or chemotherapy treatment for cancer
  • some medications, such as opiate painkillers and corticosteroids (eg, steroid injections)
  • hormone disorders (pituitary tumors or diseases, high levels of prolactin)
  • chronic diseases, such as liver and heart disease
  • obesity
  • sleep disorders
  • type 2 diabetes
  • excessive alcohol consumption
  • some genetic conditions (eg, Klinefelter syndrome, haemochromatosis, Kallmann syndrome)
  • anabolic steroids.

Symptoms of testosterone deficiency
Common symptoms
  • loss of spontaneous morning erections
  • low libido
  • erectile dysfunction
  • enlarged and painful breasts (gynaecomastia)
  • inability to father children
Uncommon or vague symptoms
  • reduced testicle size
  • reduced energy or mood
  • decreased muscle mass and strength
  • less body hair
  • bones easily broken
  • hot flushes and night sweats

A low testosterone level by itself doesn't need treatment. Testosterone replacement therapy (TRT) can have side effects, and the long-term risks and benefits aren't known.

Only men with symptoms of low testosterone and blood tests that confirm this should consider testosterone replacement. Men with testosterone levels in the bottom of the normal range (ie, still normal) are generally not treated with TRT. Read more about testosterone replacement therapy.

Close follow up is needed with your doctor. Blood tests are done every few months to monitor testosterone levels and blood count. Sometimes other tests are done, such as to monitor PSA levels.

The following lifestyle changes can help to maintain a healthy level of testosterone:

  • lose weight if you are overweight
  • keep active and exercise regularly
  • get enough sleep (at least 7 hours per night)
  • don't drink too much alcohol
  • reduce stress. 

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Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Dr Jeremy Steinberg, FRNZCGP

Last reviewed:

Page last updated: