>>16865790https://www.mayoclinic.org/diseases-conditions/male-hypogonadism/symptoms-causes/syc-20354881Primary hypogonadism
Klinefelter syndrome. This condition results from a congenital abnormality of the sex chromosomes, X and Y. A male normally has one X and one Y chromosome. In Klinefelter syndrome, two or more X chromosomes are present in addition to one Y chromosome.
The Y chromosome contains the genetic material that determines the sex of a child and related development. The extra X chromosome that occurs in Klinefelter syndrome causes abnormal development of the testicles, which in turn 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 aren't descended at birth.
This condition often corrects itself within the first few years of life without treatment. If not corrected in early childhood, it can lead to malfunction of the testicles and reduced production of testosterone.
Mumps orchitis. A mumps infection involving the testicles that occurs during adolescence or adulthood can damage the testicles, affecting the function of the testicles 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 they're outside the abdomen, the testicles are prone to injury. Damage to both testicles can cause hypogonadism. Damage to one testicle might not impair total 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, preserving sperm before starting cancer therapy is an option for men.
