You've asked yourself. Now, go ask your doctor.

What is the role of testosterone ]?

Before you learn about hypogonadism, get an understanding of what testosterone does.

Key takeaways:

  • The effects of testosterone go beyond sexual characteristics and function.
  • Testosterone levels between 300 ng/dL and 1000 ng/dL are considered normal.
  • Testosterone is made in the testes. The brain and testes work together to keep testosterone levels within the normal range.
Watch video: The Biology of Testosterone
The Biology of Testosterone video

Testosterone is a hormone made in a man's testes.

Some of the body functions that testosterone helps maintain include:
  • Reproductive tissues
  • Sperm production
  • Hair growth and distribution
  • Muscle mass and strength
  • Bone density and strength
  • Distribution of fat

Total Testosterone Levels (ng/dL)

Testosterone levels as measured in blood (ng/dL) Testosterone levels as measured in blood (ng/dL)

The lower limit of the normal range may vary by lab or test used.

There is a numerical range of testosterone levels which is considered normal. Testosterone levels obtained through blood tests are typically measured in nanograms per deciliter (ng/dL). Levels between 300 ng/dL and 1000 ng/dL are generally considered in the normal range.

The brain and the testes work together to keep testosterone levels in this range. When levels are below the normal range, the hypothalamus and pituitary gland in the brain signal the testes to make more. When there is enough, they signal the testes to make less.

Close Close

Erectile dysfunction (ED): The inability to achieve or sustain an erection for sexual intercourse.

Close Close

Hematocrit: The proportion of your total blood volume that is composed of red blood cells.

Close Close

Hormone: A chemical substance made in one part of the body that travels through the bloodstream and affects cells and tissues in another part of the body by increasing or decreasing its functional activity.

Close Close

Hypogonadism: The medical condition, sometimes known as Low Testosterone, can be caused by certain medical conditions. It can occur when the body doesn't make enough testosterone because of a problem with the testes and/or parts of the brain that regulate the testes.

Close Close

Hypothalamus: The area of the brain that controls a large number of normal functions throughout the body. The hypothalamus also regulates the functions of the pituitary gland by directing the pituitary to stop or start production of its hormones.

Close Close

Pituitary gland: An endocrine gland suspended beneath the brain that produces hormones that control other glands and many body functions, including growth, reproduction, and other metabolic activities.

Close Close

Prostate-specific antigen (PSA): A protein that is produced by the prostate. High PSA levels may be a sign of certain prostate conditions, such as an enlarged prostate, prostate infection, or prostate cancer.

Close Close

Testes: The male reproductive organs located in the scrotum. They produce sperm and the male hormone testosterone.

Close Close

Testosterone: A hormone involved in the development of male sex organs. It's one of the most important male sex hormones. Testosterone increases body and facial hair, deepens the voice, is involved in sperm cell production, and influences sexual desire and function.