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.