The prostate is a gland located beneath the bladder, behind the pubic bone and base of the penis and in front of the rectum. Shaped like a crab apple and weighing only about an ounce in young men, the prostate surrounds the urethra (the tube that carries urine away from the bladder and transports semen during ejaculation). The prostate is not a component of the urinary system, but with its proximity to the urethra it can affect urinary function.
A healthy prostate does not interfere with the flow of urine from the bladder. But in men with an enlarged prostate, the tissue closest to the urethra begins to grow, causing it to become overgrown, or enlarged. This overgrowth of prostate tissue is called benign prostatic hyperplasia (BPH). The enlarging tissue puts pressure on the urethra and ultimately restricts urine flow. The bladder must then work harder to push urine through the constricted tube.
Over time, the overworked bladder develops a thickened wall, which reduces the organ’s capacity to store urine. In about half of men with BPH, these developments lead to urinary symptoms such as a delayed or weak urine stream, increased urinary frequency or urgency, the need to get up during the night to urinate, and painful urination.
BPH is the most common prostate problem for men older than age 50. It is estimated that 14 million men in the United States experience lower urinary tract symptoms.