Causes, incidence, and risk factors

Normally, the hypothalamus in the brain releases gonadotropin-releasing hormone (GnRH). This hormone stimulates the pituitary gland to release other hormones, including follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

Normally, these hormones tell the female ovaries and male testes to release hormones that lead to normal sexual development in puberty.

• Before puberty, any change in this hormone release chain causes a lack of sex hormones and prevents normal sexual maturity.

• If the problem occurs after puberty, sexual development may be normal, but there may be symptoms of low sex hormones (such as symptoms of menopause in women and sexual dysfunction in men).

Kallmann syndrome is an inherited form of hypogonadotropic hypogonadism that can occur with a loss of smell.

Symptoms

• Erectile dysfunction in men

• Inability to smell (in some cases)

• Lack of development at puberty (development may be incomplete or delayed)

• Lack of secondary sexual characteristics such as pubic, facial, and underarm hair

• Loss of menstrual periods in women

• Short stature (in some cases)

• Underdeveloped testicles

Signs and tests

Tests that may be done include:

• Blood tests to measure hormone levels

• LH response to GnRH

• MRI of the head (to look for a noncancerous growth in the pituitary gland)

Treatment

Treatment depends on the source of the problem, but may involve:

• Estrogen and progesterone pills

• GnRH injections

• Injections of testosterone

• Slow-release testosterone skin patch

• Surgery to remove a pituitary tumor

• Testosterone gels

Expectations (prognosis)

With the right hormone treatment, the person can go through puberty and fertility may be restored.

Complications

• Delayed puberty

• Infertility

• Low self-esteem due to late start of puberty (emotional support may be helpful)

• Sexual dysfunction

Calling your health care provider

Call your health care provider if your child does not enter puberty as expected.

Prevention

Prevention depends on the cause.

People who have a family history of inherited conditions that cause hypogonadism may benefit from genetic counseling. Preventing serious head injuries reduces the risk of hypogonadotropic hypogonadism due to pituitary injury.