Some men have a penis that curves to the side, upward or downward when erect. This is common, and a bent penis in most men isn't a problem. Generally, a bent penis is only a cause for concern if your erections are painful or if the curvature of your penis interferes with sex.

When you become sexually aroused, blood flows into spongelike spaces inside your penis, expanding and stiffening it. A bent penis generally occurs when these spaces don't expand evenly. Most often, this is due to normal differences in penis anatomy, but sometimes scar tissue or another problem causes a bent penis and painful erections.

Possible underlying causes of a bent penis include:

• Peyronie's disease (a curved erection caused by one of a number of underlying conditions)
• Injury to the penis
• Autoimmune disorders
• Inherited fibrous tissue (collagen) abnormality

A bent penis usually doesn't require treatment. However, if you have a severely bent penis that causes pain or interferes with sex, see a doctor. You might need to see a doctor who specializes in sexual and urinary problems (urologist).