For a man, benign prostatic hyperplasia (BPH) is a more inevitable part of the aging process than gray hair. When a man reaches his mid-20s, his prostate embarks on a second period of growth, and continues to enlarge for most of the rest of his life.

While benign means "non-cancerous," and while BPH usually does not affect sexual function, the prostate -- as it enlarges -- presses against the bladder and urethra, cutting down the flow of urine.

A gland that started out in adult life the size of a walnut may, by age 40, have grown to the size of an apricot, and by age 60, it might be as large as a lemon. More than half of all men in their 60s and as many as 90 percent in their 70s and 80s have some symptoms of BPH.

While the symptoms of BPH vary, the most common ones are problems with urination. These include:

• A hesitant, interrupted, weak stream;
• Urgency and leaking or dribbling;
• More frequent urination, especially at night.

But the problems posed by prostate enlargement vary in severity from one man to another. While BPH cannot be cured, early symptoms will not necessarily grow more severe, or may worsen very slowly. Only about half the men with enlarged prostates will develop symptoms bothersome enough to seek medical treatment.

Men whose symptoms are mild often opt for an approach called "watchful waiting." The U.S. Public Health Service Clinical Practice Guidelines call watchful waiting "an appropriate treatment strategy for the majority of patients."

If the condition begins to pose a danger to the patient's health or causes a major inconvenience to him, treatment is then recommended. For those men for whom "watchful waiting" is not enough, drugs or surgery can help.

BPH Drug Therapy

Millions of American men in the last decade have chosen drug therapy over surgery for BPH. Drugs are regarded as less effective than surgery, but are also less invasive and generally free of major side effects.

Two major classes of drugs are used to treat BPH: alpha adrenergic blockers and finasteride.

Alpha adrenergic blockers, originally used for the treatment of high blood pressure, relax the muscular portion of the prostate and the bladder neck, allowing urine to flow more freely. In the average patient, these drugs increase the rate of urine flow and reduce symptoms, often within days.

Finasteride shrinks the prostate by blocking an enzyme that converts the male hormone testosterone into a more potent, growth-stimulating form.

Some doctors think that combining the two types of drugs may produce optimum results.

BPH Surgery

Although prostate surgery has diminished in the decade since drug therapy became available, operations for BPH remain the most common surgery performed on American men. Several types of surgery can relieve BPH symptoms: They are:

Transurethral Resection of the Prostate (TURP). A slim fiberoptic tube is inserted through the penis and up the urethra as far as the prostate. Using either a tiny blade or an electric loop, the surgeon pares away the urethras lining and bits of excess prostate tissue, expanding the passageway is expanded. TURF typically doubles the urinary flow within weeks.

Transurethral Incision of the Prostate (TUIP). An instrument is inserted through the penis to reach the prostate, but the surgeon makes only one or two small cuts to relieve pressure in the prostate rather than trimming away tissue. Like TURP, the procedure considerably increases the urine flow.

Transurethral Needle Ablation (TUNA). A catheter is inserted into the uretha that deploys needles toward the obstructing prostate tissue. Radio frequency energy is then delivered through needles to kill excess prostate tissue.

Open Prostatectomy. A surgeon makes an incision through either the lower abdomen or the perineum to reach the prostate, instead of inserting an instrument through the urethra. This procedure is used only on extremely large prostates.

The best approach for treating BPH is not clear. The U.S. Public Health Service Clinical Practice Guidelines advise doctors to leave treatment decisions to the patient, after a discussion of the benefits and side effects of each treatment option.

Having BPH does not seem to increase the chances of getting prostate cancer. Nevertheless, a man who has BPH may have undetected prostate cancer at the same time or may develop prostate cancer in the future.