It is common for the prostate gland to become enlarged as a man ages. Doctors call the condition benign prostatic hyperplasia (BPH), or benign prostatic hypertrophy. As a male matures, the prostate goes through two main periods of growth. The first occurs early in puberty, when the prostate doubles in size. At around age 25, the gland begins to grow again. It is this second growth phase that often results, years later, in BPH. Though the prostate continues to grow during most of a man's life, the enlargement usually causes no problems until late in life. BPH rarely causes symptoms before age 40, but more than half of men in their sixties and as many as 90 percent in their seventies and eighties have some symptoms of BPH.
As the prostate enlarges, the surrounding capsule stops it from expanding, causing the gland to press against the urethra like a clamp on a garden hose. The bladder wall becomes thicker and irritable. The bladder begins to contract even when it contains small amounts of urine, causing more frequent urination. As the bladder weakens, it loses the ability to empty itself, and urine remains behind. This narrowing of the urethra and partial emptying of the bladder cause many of the problems associated with BPH. Many people feel uncomfortable talking about the prostate, since the gland plays a role in both sex and urination. Still, prostate enlargement is as common a part of aging as gray hair. As life expectancy rises, so does the occurrence of BPH. In the United States alone, 350,000 operations take place each year for BPH.
It is unclear whether certain groups face a greater risk of getting BPH. Conducted studies suggest that BPH occurs more often among married men than single men and is more common in the United State and Europe than in other parts of the world. However, experts have debated these findings, and no definite information on risk factors exists. The cause of BPH also baffles experts. For centuries, it has been known that BPH occurs mainly in older men and that it does not develop in males whose testes were removed before puberty. For this reason, some researchers believe that factors related to aging and the testes may spur the development of BPH. Throughout their lives, men produce both testosterone, an important male hormone, and small amounts of estrogen, a female hormone. As men age, the amount of active testosterone in the blood decreases, leaving a higher proportion of estrogen. Studies done with animals have suggested that BPH may occur because the higher amount of estrogen within the gland increases the activity of substances that promote cell growth.
Another theory focuses on dihydrotestosterone (DHT), a substance derived from testosterone in the prostate, which may help control its growth. Most animals lose their ability to produce DHT as they age. However, some research has indicated that even with a drop in the blood's testosterone level, older men continue to produce and accumulate high levels of DHT in the prostate. This accumulation of DHT may encourage the growth of cells. Scientists have also noted that men who do not produce DHT do not develop BPH.
Some researchers suggest that BPH may develop as a result of "instructions" given to cells early in life. According to this theory, BPH occurs because cells in one section of the gland follow these instructions and "reawaken" later in life. These "reawakened" cells then deliver signals to other cells in the gland, instructing them to grow or making them more sensitive to hormones that influence growth.
Sometimes a man may not know he has any obstruction until he suddenly finds himself unable to urinate at all. This condition, called acute urinary retention, may be triggered by taking over-the-counter cold or allergy medicines. Such medicines contain a decongestant drug, known as a sympathomimetic, which may, as a side effect, prevent the bladder opening from relaxing and allowing urine to empty. When partial obstruction is present, urinary retention also can be brought on by alcohol, cold temperatures, or a long period of immobility. Tell your doctor about urinary problems. In eight out of 10 cases, these symptoms suggest BPH, but they also can signal other, more serious conditions that require prompt treatment.
