In many men, the prostate gland grows until around the age of 20 and then experiences another "growth spurt" beginning at age 45. Depending on the type of disease, prostate diseases can affect men of all ages. An infection or inflammation known as prostatitis is more likely to infect young and middle aged men. After the age of 45, men may experience benign prostatitis hyperplasia (BPH), which is essentially an enlarged prostate. BPH has similar symptoms to prostate cancer, which is also common in older men.