Peyronie’s disease is a chronic inflammatory disease that causes scar tissue—called plaque—to form along the length of the penis, reducing its elasticity. Depending on the location of the scar tissue, it can cause the erect penis to curve upward or to the side, which can be painful. The greater the scarring, the more pronounced the curvature of the penis.

Scar tissue can form following an injury to the penis or build up slowly over time as part of the normal aging process. As tissue in the penis becomes less elastic, small undetected tears can occur in its stretchy layers. In other parts of the body, damaged tissue is repaired naturally by the normal flow of blood to the injured area, but because very little blood circulates in the flaccid penis these tears don’t heal and scar tissue builds up. Scar tissue on the top of the shaft often causes the penis to curve skyward. In severe cases, the penis may curve back toward the abdomen like a hook. Not only can this curvature be painful and make the penis shorter, it can make intimacy difficult or impossible.

Men with diabetes, high blood pressure or high cholesterol have a higher risk for Peyronie’s disease. Smoking and the consumption of alcohol change the structure of stretchy penile tissue and can contribute to the onset of Peyronie’s. Some men may have a family history of the disease. While men of any age can be affected, Peyronie’s disease is more common in men between 40 and 70 years old.

Treatment may include oral medications, penile injections or surgery to remove plaque buildup, straighten the penis and restore erectile function.