DEAR DOCTOR K: I have BPH. Can you explain how an enlarged prostate causes troublesome urinary symptoms?
DEAR READER: Around the time of a man’s 25th birthday, his prostate gland begins to grow. This natural enlargement is called benign prostatic hyperplasia (BPH). It is the most common cause of prostate enlargement. If a man lives long enough, he will almost certainly experience some degree of BPH.
Most men with BPH never develop any symptoms, but for those who do, BPH can make life miserable. Interestingly, the size of the prostate does not always predict symptoms. Some men with large glands never have symptoms, while others with small glands do.
The most common symptoms of BPH involve changes or problems with urination. You may feel as though you have to urinate immediately, yet have to strain to do so. You may have a weak urinary stream or one that stops and starts. You may dribble after urinating or feel as if you’re not emptying your bladder completely. And you may feel the need to urinate frequently, causing many awakenings during the night.
The symptoms of BPH typically start slowly and fitfully and creep up on you over time. If you have never had the slightest suggestion of these symptoms, and suddenly for the last day or two you have had these symptoms, it’s probably not BPH. You may have a urinary infection, particularly if it burns when you urinate.
Other conditions besides a urinary infection can sometimes cause similar symptoms to BPH. That includes cancer of the bladder and of the prostate gland. It also includes stones in the bladder, and damage to the nerves leading to the bladder from various conditions (including diabetes).
Before making a diagnosis of BPH, the doctor should do a rectal examination of a patient’s prostate. In addition, the doctor usually orders a test of chemicals and cells in the urine (a urinalysis), kidney function tests (BUN and creatinine) and a PSA test (to look for signs of prostate cancer).
As the prostate enlarges, it starts to press against the urethra and the bladder. It’s like a foot stepping on a garden hose or fingers pinching a soda straw. (I’ve put an illustration of this on my website, AskDoctorK.com.) This gradually obstructs the flow of urine, forcing the bladder to work harder to push urine through the urethra.
But straining to urinate, although unavoidable, only makes matters worse. This extra work makes the bladder wall thicker, reducing the amount of urine the bladder can hold. And it causes the bladder to contract even when it contains only small amounts of urine, leading to more frequent urination. Eventually, the bladder becomes so thick that it loses its elasticity and can no longer empty itself.
If your symptoms are starting to interfere with your lifestyle, see your doctor. These days, there are several medications for BPH. If one doesn’t do the trick, your doctor can prescribe another. And surgical treatments, if needed, are more effective and have fewer side effects than ever before.
Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.