Men’s Health
Mechanics of
BPH Leads to Greater Understanding
by Carmin M. Kalorin, MD
The long-term result of a complex physiological response of the bladder to the enlarging prostate are irritative symptoms, such as an urgent need to urinate, voiding frequently and getting up to urinate several times a night. Benign prostatic hyperplasia (BPH) affects millions of men worldwide. Studies have shown that benign enlargement of the prostate occurs in 70 percent of men between the ages of 40 and 60; and in more than 90 percent of men over age 80. As the prostate enlarges, it can result in many of the bothersome symptoms that bring men to the doctor. The prostate is a male gland that sits between the bladder and penile urethra. In order for urine to pass, it must exit the bladder and flow through a “tunnel” created by prostate tissue surrounding the urethra. Urine then exits through the penile urethra. Normally, the prostatic urethra provides a small amount of resistance to the flow of urine. The contractile action of the bladder easily provides enough force to overcome this resistance and the result is a strong, smooth urinary stream.
Some patients begin to help the bladder generate more force by bearing down and straining to initiate the flow of urine. Other symptoms soon follow, such as weak force of stream, post void dribbling, a sensation of incomplete emptying, double voiding (having to void again soon after a previous void), inconsistent or “stop and start” stream, and urinary retention. 26
The Triangle Physician | JUNE 2010
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Early Symptoms As the prostate enlarges the growing tissue surrounding the urethra compresses the walls of the tunnel. As this tunnel narrows, the resistance to flow greatly increases. The bladder has to contract more forcefully to overcome the increased resistance.