Hormones play a big role in men’s health, affecting your energy level, weight, mood, interest in sex, fertility and much more.  How hormones affect the health of men, and women, too—changes as you age so it’s important to stay informed.

What is the role of testosterone in men’s health?
Testosterone is the most important sex hormone that men have.  It is responsible for the typical male characteristics, such as facial, pubic, and body hair as well as muscle.  This hormone also helps maintain sex drive, sperm production, and bone health.  The brain and pituitary gland (a small gland at the base of the brain) control the production of testosterone by the testes.


In the short term, low testosterone (also called hypogonadism) can cause:

• A drop in sex drive
• Poor erections
• Low sperm count
• Enlarged breasts

Over time, low testosterone may cause a man to lose body hair, muscle bulk, and strength and to gain body fat. Chronic (long-term) low testosterone may also cause weak bones (osteoporosis), mood changes, less energy, and smaller testes.  Signs and symptoms (what you see and feel) vary from person to person.
 

What causes low testosterone?

Low testosterone can result from:

• Testicular injury (trauma, castration) or infection
• Radiation or chemotherapy treatment for cancer
• Some medications, such as opiate painkillers
• Hormone disorders (pituitary tumors or diseases, high levels of prolactin)
• Chronic diseases, such as liver and kidney disease, obesity, type 2 diabetes, and HIV/AIDS
• A genetic condition (Klinefelter syndrome)

How is low testosterone treated?
Testosterone replacement therapy can improve sexual interest, erections, mood and energy, body hair growth, bone density, and muscle mass.  There are several ways to replace testosterone:

• Gel or patches that you put on your skin
• Injections (shots)
• Pellets inserted under the skin (buttock)

The best method will depend on your preference and tolerance, and the cost.
 

Questions to ask your doctor:

• What is the cause of my low testosterone?
• Is testosterone replacement an option for me?
• should I get my testosterone level retested?

Blood tests determine whether testosterone levels are in the normal range. This is generally 300-1,000 ng/dL, but the normal range may differ depending on the laboratory that conducts the test.  To diagnose low testosterone, it is recommended to have blood drawn in the early-morning when levels are at their highest.