Living Better with Benign Prostatic Hyperplasia

Causes and effects

In benign prostatic hyperplasia (BPH), cells in the prostate gland start to divide and grow again for the first time since young adulthood. That’s what causes the gland to expand in size, from an average of 30 grams in a normal prostate (about an ounce) up to, not uncommonly, 140 or even 150 grams (up to five ounces). In rare cases, prostate size may exceed 300 grams (10 ounces).

The prostate is made up of muscle tissue and a network of tiny tubes (ducts) lined with cells that produce prostatic fluid. During ejaculation, the prostate pushes that fluid through those ducts and into the urethra, where it mixes with sperm cells and exits through the penis. BPH is the result of cell overgrowth in the muscle as well as the lining of the ducts.

What exactly switches prostate growth back on in middle age remains a bit of a mystery, although there are theories. Prostate enlargement may have something to do with an age-related buildup of dihydrotestosterone, a hormone that plays a central role in the development of the penis and prostate as the fetus grows during pregnancy. Certain factors are linked to a higher risk of BPH. These risk factors include increasing age, a family history of BPH, higher body weight, and lack of exercise. It’s not clear whether losing weight or exercising more actually prevents BPH, but these factors can identify men who are the most likely to develop prostate enlargement with bothersome urinary problems.

Crowded anatomy

Part of the reason prostate enlargement causes problems is the crowded anatomy of the pelvic region. Notably, the bladder is sandwiched between the pubic bone and the wall of the rectum, the last part of the colo.  The prostate also sits just below the bladder. All of this doesn’t give the bladder much room to move if the prostate begins to expand.

Another problem: the prostate wraps entirely around the urethra at the point where it exits the bladder. As the prostate grows, it starts to press in on the urethra and restrict the flow of urine (see Figure 2, page 5). As a result, it gets harder to empty your bladder. In some cases, the impingement can get so extreme that you can’t urinate at all—a medical emergency that poses the risk of kidney damage.

Bladder malfunction

With continued obstruction to urine flow, the muscles in the bladder wall have to work much harder to push urine out of the body. Straining to urinate eventually starts to affect the function of the bladder itself. As the bladder wall thickens and loses some of its natural “give,” it can store less urine. That means more frequent trips to the bathroom.

In addition, the nerves that sense a full bladder and coordinate the normal emptying of the bladder may start to malfunction. Known as overactive bladder, this condition causes abnormal contractions of the bladder wall that unleash a sudden and disruptive urge to urinate.

BPH or prostate cancer?

It’s important to know that prostate cancer can also cause lower urinary tract symptoms very similar to those of BPH, though usually at a relatively advanced stage of the disease. This is why men being evaluated for BPH undergo a blood test to screen for possible prostate cancer.

If you start to notice bothersome urinary symptoms, there is no need to worry unduly about prostate cancer. Noncancerous BPH is the far more likely explanation, but you should check it out. Urinary problems are common, and there are many ways to treat them.