Peyronie's disease is characterized by a plaque that forms on the penis, which can cause reduced flexibility and pain. The plaque itself is benign (noncancerous). In men with severe cases of the disease, the hardened plaque reduces flexibility, causing pain and forcing the penis to bend or arc during an erection. Peyronie's disease occurs mostly in middle-aged men; but men of any age can develop it. Although the cause of Peyronie's disease and its development are not well understood, many researchers believe that the plaque associated with the disease develops following trauma (hitting or bending) that causes localized bleeding inside the penis. The sexual problems caused by this disease can disrupt a couple's physical and emotional relationship. The goal of treatment for Peyronie's disease is to keep the patient sexually active. Surgery is recommended only for long-term cases of Peyronie's disease.