Hypogonadism (low testosterone)
Testosterone is the “male” hormone; it is responsible for the changes that occur in boys during puberty including deepening of the voice, growth of body hair, enlargement of the penis, development of muscle mass, and production of sperm. Testosterone plays an important role in adult men, specifically maintaining these biological functions and also playing a role in sexual function and libido.
Low testosterone (sometimes referred to as hypogonadism) is the condition in which blood levels of testosterone are lower than expected. This can be due to certain medical conditions, stress, or problems with the pituitary gland or testicles that may be the result of certain congenital issues, infections, or treatments such as radiation or chemotherapy. Testosterone levels also tend to decline with age.
Many men with low blood levels of testosterone are completely asymptomatic; however, men with low T are more likely than other men to report changes in sex drive or erections, fatigue, loss of muscle mass, irritability, poor sleep, and infertility.
It is important to note that the lab tests used to measure testosterone are subject to a great deal of variability; for this reason it is essential that at least two morning testosterone levels be obtained before making a diagnosis of low T. It is also important to note that many men with low blood levels of testosterone are completely asymptomatic and appear completely healthy. Treatment of low T is appropriate for men with both low blood levels AND signs/symptoms potentially referable to low T
Adult men with low testosterone may be treated with testosterone replacement therapy; in some cases this treatment may lead to improvements in sexual function, energy, mood, and muscle mass. Testosterone can be delivered in several ways, including through injections, patches and gels. Men who clearly benefit from testosterone can consider implantation of small pellets that release testosterone over a period of several months. If a pituitary problem is the underlying cause of hypogonadism, surgery or replacement pituitary hormones may be indicated.
Testosterone therapy is NOT a treatment for infertility. In fact, treatment with testosterone is very likely to make fertility worse. However, there are some options for managing low testosterone in men who want to preserve fertility. While typically not as effective at raising testosterone levels, these options may be indicated in some cases.
Testosterone therapy is generally safe but is not without risks and some unknowns about long term use. It is important for men taking testosterone to have routine measurement of T levels as well as related labs such as blood count, prostate specific antigen, and other tests as indicated. Some experts have raised concerns about the effects of testosterone on the heart and prostate gland; for these reasons a detailed conversation about risks and benefits should occur before starting.
It is important to note that the symptoms associated with low testosterone are very general; in others, low testosterone may not be the root cause of a given man’s symptoms, even if he also has a low blood level of testosterone. Not all men with low testosterone and symptoms will benefit from testosterone supplementation. If a man taking testosterone has normalization of his blood levels but still does not experience clinical improvements within three months he may need to consider alternative causes or treatments for his symptoms.