Benign prostatic hyperplasia, or BPH for short, is the enlargement of the prostate gland. It is caused by excess growth of cells in the prostate. This condition is not the same as prostate cancer.

What is going on in the body?

The prostate is a walnut-sized gland that is part of the male reproductive system. This gland surrounds the urethra, the tube that carries urine from the bladder out of the body. The job of the prostate is to squeeze fluid into semen to help with fertility. The prostate responds to testosterone, the main male hormone. After puberty, it doubles in size. Around age 25, it grows again and continues to grow slowly throughout a man's life. This enlargement does not usually cause problems until later in life. BPH rarely causes symptoms before age 40. But more than half of men in their 60s and up to 90% in their 70s have some symptoms of BPH. In some men, the enlarged prostate can cause a blockage of the bladder outlet known as prostatism. Although the actual causes are more complex, it is helpful to think of BPH as a blockage of urine flow by an enlarging prostate.

What are the causes and risks of the condition?

The cause of BPH is not well understood. Some experts think that factors related to aging and changing hormone levels may spur the development of BPH.

The primary risk of BPH is that urine flow may be blocked. This can sometimes cause kidney damage, bladder stones, and urinary tract infections.