Common Causes of Primary Hypogonadism
Klinefelter syndrome. This condition results from a congenital abnormality of the sex chromosomes which leads to abnormal development of the testicles and results in underproduction of testosterone.
Undescended testicles. Before birth, the testicles develop inside the abdomen and normally move down into their permanent place in the scrotum. Sometimes, one or both of the testicles may not be descended at birth. This condition often corrects itself within the first few years of life without treatment. If not corrected in early childhood, it may lead to malfunction of the testicles and reduced production of testosterone.
Mumps orchitis. If a mumps infection involving the testicles in addition to the salivary glands (mumps orchitis) occurs during adolescence or adulthood, long-term testicular damage may occur. This may affect normal testicular function and testosterone production.
Hemochromatosis. Too much iron in the blood can cause testicular failure or pituitary gland dysfunction affecting testosterone production.
Injury to the testicles. Because of their location outside the abdomen, the testicles are prone to injury. Damage to normally developed testicles can cause hypogonadism. Damage to one testicle may not impair testosterone production.
Cancer treatment. Chemotherapy or radiation therapy for the treatment of cancer can interfere with testosterone and sperm production. The effects of both treatments often are temporary, but permanent infertility may occur. Although many men regain their fertility within a few months after treatment ends, preserving sperm before starting cancer therapy is an option that many men consider.
Normal aging. Older men generally have lower testosterone levels than younger men do. As men age, there’s a slow and continuous decrease in testosterone production.