The prostate is a walnut-sized gland that forms part of the male reproductive system. The gland is made of two lobes enclosed by an outer capsule.The prostate is located in front of the rectum and just below the bladder. It also surrounds the urethra, (through which urine passes out of the body).
Doctors do not know all the functions of the prostate. One of its main roles, however, is to squeeze fluid into the urethra as sperm move through during sexual orgasm. This prostate fluid, which helps make up semen, energizes the sperm and makes the vaginal canal more hospitable to them.
It is common for the prostate gland to become enlarged as a person grows older. This condition is called "benign prostatic hyperplasia" (BPH), or "benign prostatic hypertrophy". As a man matures, the prostate goes through two main periods of growth. The first occurs early in puberty, when the prostate doubles in size. Then, at about age 25, the gland begins growing again. This second phase may ultimately result in BPH.
Although the prostate grows during most of a man's life, the enlargement doesn't usually cause problems for many years. BPH rarely causes symptoms before age 40, but more than half of men in their sixties and up to 90 percent in their seventies and eighties have symptoms of BPH.
As the prostate enlarges, the capsule surrounding it stops it from expanding and causes the gland to press against the urethra. The bladder wall becomes thicker and irritable and begins to contract even when it contains small amounts of urine. Over time, the bladder loses the ability to empty completely. The narrowing of the urethra and partial bladder emptying cause many of the problems associated with BPH.
Because of the prostate's role in sex and urination, many people feel uncomfortable talking it. Still, prostate enlargement is a common part of aging, and as life expectancies rises, BPH becomes more common. In 2000, there were 4.5 million visits to physicians for BPH in the United States.