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Alternative names: Gonadal Deficiency, Testosterone Deficiency

What is male hypogonadism?

Male hypogonadism is caused by a man's testes failing to produce normal levels of the male sex hormone, testosterone. Some men are born with hypogonadism, while others may develop the condition later in life.

There are two kinds of male hypogonadism:

  • Primary hypogonadism in which the testes do not work properly
  • Secondary hypogonadism in which the testes are not being stimulated to produce hormones. This happens because of a problem with the pituitary or hypothalamus glands, such as a tumor.

What are the signs of male hypogonadism?

Male hypogonadism at puberty can slow a boy's growth, and affect the development of normal male sexual characteristics. He may not undergo the normal changes a boy has during puberty, such as a deepening voice, body and facial hair, and increased muscle mass.

Male hypogonadism in adults can cause

  • Impotence, or the inability to perform sexually
  • Lack of interest in sex
  • Fatigue and loss of energy
  • Reduced growth of facial hair
  • Reduced sperm production, causing infertility
  • Increase in body fat, and/or development in breast tissue
  • Osteoporosis 

What causes male hypogonadism?

Primary hypogonadism, in which the testes do not work properly, can be caused by many conditions, including:

  • Klinefelter's syndrome, an inherited (genetic) condition. This is sometimes called " XXY males."
  • Improper development of the testes (testicular agenesis)
  • Undescended testes, in which the testes are located in the body, instead of in the scrotum
  • Damage to the testes, caused by infection, disease, or injury
  • Surgical removal of both testes, as a treatment for testicular cancer
  • Radiation or chemotherapy, as a treatment for testicular cancer

Secondary hypogonadism, in which the endocrine glands do not stimulate the testes to produce hormones, can be caused by:

  • Tumors of the pituitary gland
  • Damage to the pituitary or hypothalamus glands, caused by infection, disease, or injury
  • Surgery that affects the pituitary or hypothalamus glands
  • Radiation treatments for cancer
  • Excessive iron in the blood (hemochromatosis)
  • Genetic disorders, such as Kallman syndrome
  • Taking certain medications, such as opiates and replacement hormones

How does my doctor tell if I have male hypogonadism?

Your doctor may check for low levels of testosterone (male sex hormone) by performing a blood test. He or she may also use blood tests to check the levels of the pituitary hormones (FSH and LH) that stimulate the testes to produce their hormones.

Other laboratory tests can help your doctor tell if hypogonadism is being caused by a problem with the testes, or with the pituitary gland. Such tests include:

  • Semen analysis
  • Computed tomography (CT) and magnetic resonance imaging (MRI) scans of the head and brain, to check for pituitary tumors
  • A biopsy of the testes, in which a small sample of cells is removed from the testes, and studied in a laboratory
  • Genetic studies

How is male hypogonadism treated?

If male hypogonadism is caused by a pituitary or other tumor, treatment is aimed at removing the tumor, or reducing its effects. This can include medication, surgery, and/or radiation therapy.

Male hormone replacement therapy has been used successfully for years to treat male hypogonadism. This involves a man taking testosterone by injection, transdermal system (patch), or gel.

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