Doctors classify hypogonadism as either primary or secondary. Both classes of hypogonadism involve inadequate production of hormones by the sex glands--the ovaries in women and the testes in men. In primary hypogonadism, improper functioning of the testes or ovaries causes the condition. In secondary hypogonadism, the causes are connected with the hypothalamus and the pituitary gland. The underlying causes of the malfunctions of those organs or glands may have genetic origins, or may be due to an illness or certain medical procedures.
Klinefelter Syndrome
The genetic disorder known as Klinefelter syndrome is the most common hereditary cause of hypogonadism in men, notes MedlinePlus. That syndrome occurs in approximately one in every 700 births of male babies, notes the Merck Manuals for Healthcare Professionals. Males with Klinefelter syndrome have an extra X chromosome, and require lifelong testosterone treatment after puberty. The condition causes reduced production of sperm and hormones, and many men with the condition are infertile. Fifteen percent of these men, however, may have cells that might mutate while they divide--a condition known as mosaicism-- and they could be fertile, notes the Merck Manuals.
Turner Syndrome
Turner syndrome is the most common genetic cause of female primary hypogonadism. Also known as gonadal dysgenesis, or Bonnevie-Ullrich syndrome, it occurs in approximately one in every 2,000 births, notes the University of Maryland Medical Center. Those born with this syndrome lack a complete second chromosome, and at puberty may not develop sexual characteristics and may not menstruate.
Kallman Syndrome
Kallman syndrome affects only males, and causes secondary--or central--hypogonadism. People with this condition also lack a sense of smell, and 80 percent experience involuntary finger movement known as synkinesia, according to the University of Nebraska Medical Center. Infants with the syndrome usually have cryptorchidism, which means that one or both testicles do not descend at birth. Adolescents may not mature sexually, and adults with the condition may experience low libido and infertility.
Illnesses and Medical Procedures
MedlinePlus notes that infections, kidney disease, liver disease and autoimmune disorders may cause primary hypogonadism. MayoClinic.com mentions that if an adult or adolescent gets mumps and the illness affects the testicles, it may cause hypogonadism. Radiation and surgical procedures can cause both primary and secondary hypogonadism. Other causes of secondary hypogonadism include trauma and the rapid loss of a significant amount of weight. Excessive levels of iron in the blood--a condition known as hemochromatosis--can cause the testes or the pituitary gland to function improperly, which can result in hypogonadism, explains MayoClinic.com.
