Enlarged Prostate (Benign Prostatic Hyperplasia)

What Is It?

The prostate is a small gland approximately the size and shape of a walnut. It sits directly below the bladder, in front of the rectum. The prostate is a part of the male reproductive tract. It produces fluid that combines with sperm to make semen.

At birth, the prostate gland is tiny. When testosterone levels rise during puberty, the prostate grows rapidly, doubling in size by age 20. Growth slows down for the next two decades and the prostate usually does not cause problems for many years. Less than 10% of 30-year-old men have an enlarged prostate. When a man reaches his 40s, the prostate goes through a second growth spurt. Half of all men have an enlarged prostate by the time they reach age 60, and by age 85, 90% of men have an enlarged prostate.

As you age, your prostate can grow from the size of a walnut to about the size of a lemon. It's not clear why the prostate grows like this, but it's believed certain male hormones such as dihydrotestosterone tend to act more strongly on the prostate gland later in life.

Because the prostate is located just below the bladder, when it becomes larger it can place pressure on the urethra, the tube that carries urine from the bladder through the penis and out of the body. This may lead to a variety of urination problems.

For example, you may have trouble beginning to urinate, continue to dribble afterward and feel like you have not fully emptied your bladder. Urine that doesn't get expelled and collects in the bladder can increase the risk of infection, which in turn makes it painful to urinate and causes even more bathroom trips and potentially loss of bladder control. Urinary tract (or bladder) infections can also lead to a kidney infection.