(HYPERGONADISM)
WHAT’S THE DEAL WITH TESTOSTERONE?
Testosterone is the major sex hormone in males and plays a number of important roles, such as:
- The development of the penis and testes
- The deepening of the voice during puberty
- The appearance of facial and pubic hair starting at puberty; later in life, it may play a role in balding
- Muscle size and strength
- Bone growth and strength
- Sex drive (libido)
- Sperm production
Adolescent boys with too little testosterone may not experience normal masculinization. For example, the genitals may not enlarge, facial and body hair may be scant and the voice may not deepen normally. Testosterone may also help maintain a normal mood. There may be other important functions of this hormone that have not yet been discovered.
Signals sent from the brain to the pituitary gland at the base of the brain control the production of testosterone in men. The pituitary gland then relays signals to the testes to produce testosterone. A “feedback loop” closely regulates the amount of hormone in the blood. When testosterone levels rise too high, the brain sends signals to the pituitary to reduce production.
If you thought testosterone was only important in men, you’d be mistaken. Testosterone is produced in the ovaries and adrenal gland. It’s one of several androgens (male sex hormones) in females. These hormones are thought to have important effects on:
- Ovarian function
- Bone strength
- Sexual behavior, including normal libido (although evidence is not conclusive)
The proper balance between testosterone (along with other androgens) and estrogen is important for the ovaries to work normally. While the specifics are uncertain, it’s possible that androgens also play an important role in normal brain function (including mood, sex drive and cognitive function).
Did You Know?
Testosterone is synthesized in the body from cholesterol. But having high cholesterol doesn’t mean your testosterone will be high. Testosterone levels are too carefully controlled by the pituitary gland in the brain for that to occur.
THE PERILS OF TOO MUCH TESTOSTERONE
Having too much testosterone is not a common problem among men. That may surprise you given what people might consider obvious evidence of testosterone excess: road rage, fighting among fathers at Little League games and sexual promiscuity.
Part of this may be due to the difficulty defining “normal” testosterone levels and “normal” behavior. Blood levels of testosterone vary dramatically over time and even during the course of a day. In addition, what may seem like symptoms of high testosterone excess (see below) may actually be unrelated to this hormone.
In fact, most of what we know about abnormally high testosterone levels in men comes from athletes who use anabolic steroids, testosterone or related hormones to increase muscle mass and athletic performance.
Problems associated with abnormally high testosterone levels/symptoms of high testosterone in men include:
- Low sperm counts, shrinking of the testicles and impotence (seems odd, doesn’t it?)
- Heart muscle damage and increased risk of heart attack
- Prostate enlargement with difficulty urinating
- Liver disease
- Acne
- Fluid retention with swelling of the legs and feet
- Weight gain, perhaps related in part to increased appetite
- High blood pressure and cholesterol
- Insomnia
- Headaches
- Increased muscle mass
- Increased risk of blood clots
- Stunted growth in adolescents
- Uncharacteristically aggressive behavior (although not well studied or clearly proven)
- Mood swings, euphoria, irritability, impaired judgment, delusions