A testosterone level test helps determine the amount of testosterone a male’s body is naturally producing. If an individual is undergoing hormone replacement therapy, this test can also help monitor hormone levels to track the efficacy of hormone supplementation.
Testosterone is a male sex hormone that is crucial to development, especially during puberty. Low testosterone - also known as male hypogonadism - occurs when the testes do not produce enough testosterone, resulting in a hormone deficiency. Low testosterone causes different symptoms, depending on the person and their age.
Low testosterone may be present at birth or develop over years. Genetically male fetuses may experience underdeveloped genitals as a result of low testosterone. Young males with low testosterone may experience delayed puberty or underdevelopment during puberty unless the condition is treated.
Age is a common cause of low testosterone. After the age of 30, a man’s body begins to produce less testosterone. Over time, this leads to a gradual reduction in testosterone levels. Nearly 40% of men over the age of 45 experience low testosterone levels.
Aside from natural aging, other causes of low testosterone include:
- Injury to the testicles
- Chemotherapy
- Pituitary disorders such as a pituitary tumor
- Klinefelter syndrome (a condition in which a man is born with an extra X chromosome)
- Kallman’s syndrome (the abnormal development of the hypothalamus gland, which regulates hormone production)
- Hemochromatosis (too much iron in the blood)
- Liver failure
- Kidney failure
- Inflammatory conditions such as sarcoidosis or tuberculosis
- HIV/AIDS
- Medications such as opioid pain medication or hormone replacement drugs
- Anabolic steroid use
- Obesity
- Alcohol abuse