The prostate gland produces the fluid that carries sperm during ejaculation. As the prostate enlarges, which happens to almost all men as they get older, it can press on the urethra (the tube that empties urine from the bladder). This causes problems with urination.
The likelihood of developing an enlarged prostate increases with age. A small amount of prostate enlargement is present in many men over age 40 and more than 90% of men over age 80. They usually need to wake up and urinate 2 or more times per night. Some may experience urinary retention or weak urine stream. No risk factors have been identified other than having normally functioning testicles.