Diagnosis and Causes of Low Testosterone

As a man ages, the testosterone level in his body naturally declines. If testosterone levels drop dramatically, or if a man is experiencing any symptoms of low testosterone, also referred to as low T, he should be evaluated by a doctor. Dr. Paul Knoepflmacher explains what you can expect during process of diagnosing low testosterone, as well as some causes of low testosterone. 

To diagnose low testosterone, your doctor will review your medical history, which is important in determining the causes of low testosterone, a form of hypogonadism. The doctor will also give a physical examination, checking the size of the testes and breasts as well as the amount of body hair. A doctor will also look for Eunuchoid proportions, a condition associated with low testosterone. A doctor may also check a man's sperm count. A blood test is the most important in determining the level of testosterone in the blood.

After a diagnosis of low T, the next step is to determine the causes of low testosterone, and whether it is primary hypogonadism or secondary hypogonadism. Blood tests will be used to measure pituitary hormones. If primary hypogonadism is diagnosed, genetic testing may be done to determine the causes of low testosterone. If the diagnosis is secondary hypogonadism, a doctor may order an MRI to examine the pituitary gland and hypothalamus. The doctor may also test for hormone deficiencies. 

For adult men, potential causes for primary hypogonadism include injury to the testes, chemotherapy or radiation therapy, excessive alcohol consumption and cirrhosis of the liver, HIV, swelling of the testicles due to chronic kidney failure, or Klinefelter's syndrome, a rare genetic disease. 

Secondary hypogonadism can be caused by drugs, tumors and diseases affecting the brain, as well as obesity. Other causes of low testosterone include Kallmann syndrome, a genetic condition. Anorexia, gastric bypass surgery and the use of steroids is also associated with low testosterone. Newborns and boys who haven't reached puberty can also experience low testosterone due to genetic disorders. 

Once the causes of low testosterone are determined, treatment can begin. Treatment can lower the risk of complications like infertility, osteoporosis and sexual dysfunction, so it is important to talk to your doctor to find the most effective low testosterone treatment for you. 


Dr. Paul Knoepflmacher

This video features Dr. Paul Knoepflmacher. Dr. Paul Knoepflmacher is a Diplomate of the American Board of Internal Medicine

Duration: 03:47.
Reviewed by: Dr. Preeti Parikh, Dr. Holly Atkinson . Review date: December 29, 2012
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