Benign prostatic hyperplasia (BPH), also known as benign prostatic enlargement, is the most common noncancerous growth in men. As is true for prostate cancer, BPH occurs more often in Western industrialized countries (the United States, the United Kingdom and Canada, for example) than in Eastern countries (such as Japan and China).
BPH appears to be more common among black men than among white men, and some evidence suggests that a family history of BPH may increase the risk. Being overweight, especially with extra fat concentrated around the abdomen, increases the risk of developing BPH.
About 50 percent of men between the ages of 51 and 60 and up to 90 percent of those older than 80 are affected by BPH. Treatment for the condition is necessary only if symptoms begin to interfere with a man’s quality of life. The main treatment options for BPH include medications that either shrink the prostate or relax the muscle tissue that constricts the urethra; surgery to remove, ablate, or vaporize excess prostate tissue; and heat therapy called thermotherapy.
What causes BPH?
In BPH, prostate cells accumulate and the organ tissue becomes overgrown, or enlarged. Tissue overgrowth produces nodules in the transition zone of the prostate. The increase in prostate cells is due to a slowing of apoptosis (normal programmed cell death), not an increase in cell production.
What triggers BPH is not well understood, but aging and testosterone (the predominant male sex hormone) are believed to be the primary influences on its development. The female sex hormone estrogen (produced in small amounts in men) also may play a role, perhaps when a man’s testosterone production declines and the balance of the two hormones is altered.
What are the symptoms of BPH?
BPH symptoms arise only when the expanding nodules of prostate tissue (and the tightening of smooth muscle) place enough pressure on the urethra to interfere with urine flow. However, some men whose prostate is very enlarged may not have urethral obstruction, and other men with a modest enlargement may experience significant symptoms.
Constriction of the urethra leads to changes in the bladder. To compensate for the obstruction, the muscular wall of the bladder contracts more strongly to expel urine. These stronger contractions cause the bladder wall tissues to thicken and stiffen, which decreases the ability of the bladder to store urine normally. Over time, a man senses that urination is necessary at smaller and smaller volumes of urine, resulting in the need to urinate more frequently and, often, urgently.
As the urethral obstruction worsens, the contractions may no longer empty the bladder completely and urinary retention can occur. Urine retained in the bladder (residual urine) can become infected or can lead to the formation of bladder stones. Less often, the kidneys become damaged from increased pressure on them from the overworked bladder or from an infection that has spread from the bladder to the kidneys.
Urination symptoms associated with BPH include difficulty in starting to urinate; a weak urinary stream; a sudden, strong desire to urinate (urinary urgency); an increased frequency of urination; frequent nighttime urination (nocturia); and a sensation that the bladder is not empty after urinating (evidenced by straining to urinate).
When urinary retention occurs, and as the bladder becomes more sensitive to retained urine, a man may become incontinent because he is unable to respond quickly enough to urinary urgency. A bladder infection or stone can cause burning or pain during urination. Blood in the urine (hematuria) may also be a sign of BPH but most men who have the condition do not experience it.
Sometimes a man with BPH suddenly becomes unable to urinate at all, even though his condition is responding to treatment. This problem, called acute urinary retention, requires immediate medical attention in a hospital emergency room. It is easily treated with catheterization—the passing of a tube into the bladder through the urethra to allow the urine to drain.
Acute urinary retention may be triggered by an extended delay in urination, a urinary tract infection, alcohol intake, or use of certain drugs such as antidepressants, decongestants, and tranquilizers.
Acute urinary retention often occurs unexpectedly, and it is impossible to accurately predict whether a man with only modest urinary tract symptoms will develop the condition. Some men who experience acute urinary retention will need to undergo surgery to remove excess prostate tissue.