The prostate gland is a small, round lump of tissue located between the penis and the bladder. Its function is to add fluid to the semen, the liquid that carries the sperm. It tends to grow bigger as men enter middle age, and continues to grow with age. In some men the prostate gland can grow to be more than seven times its original size. This runaway growth is called hyperplasia and results in the condition benign prostatic hyperplasia (BPH).
BPH causes no symptoms or problems in two-thirds of men over the age of 50 years, but the chance of developing symptoms increases with each additional year. The prostate surrounds the top of the urethra, the tube through which we urinate, just where it meets the bladder. If the prostate gets too big, it can squeeze the urethra, partly closing it. This can lead to various bladder problems.
Having BPH doesn't increase your chances of getting prostate cancer. The two diseases can have similar symptoms, although prostate cancer often has no symptoms. It's also possible to have BPH and prostate cancer at the same time.