Peyronie's disease signs and symptoms might appear suddenly or develop gradually. The most common signs and symptoms include:

• Scar tissue. The scar tissue (plaques) associated with Peyronie's disease can be felt under the skin of the penis as flat lumps or a band of hard tissue.
• A significant bend to the penis. Your penis might be curved upward, downward or bent to one side. In some cases, the erect penis might have narrowing, indentations or an hourglass appearance, with a tight, narrow band around the shaft.
• Erection problems. Peyronie's disease might cause problems getting or maintaining an erection (erectile dysfunction).
• Shortening of the penis. Your penis might become shorter as a result of Peyronie's disease.
• Pain. You might have penile pain, with or without an erection.

The curvature associated with Peyronie's disease might gradually worsen. At some point, however, it typically stabilizes.

Pain during erections usually improves within one to two years, but the scar tissue and curvature often remain. In some cases, both the curvature and pain associated with Peyronie's disease improve without treatment.

The cause of Peyronie's disease isn't completely understood, but a number of factors appear to be involved.

It's thought Peyronie's disease generally results from repeated injury to the penis. For example, the penis might be damaged during sex, athletic activity or as the result of an accident. However, most often, no specific trauma to the penis is recalled.

During the healing process, scar tissue forms in a disorganized manner, which might then lead to a nodule that you can feel or development of curvature.

Each side of the penis contains a sponge-like tube (corpus cavernosum) that contains many tiny blood vessels. Each of the corpora cavernosa is encased in a sheath of elastic tissue called the tunica albuginea (TOO-nih-kuh al-BYOO-JIN-e-uh), which stretches during an erection.

When you become sexually aroused, blood flow to these chambers increases. As the chambers fill with blood, the penis expands, straightens and stiffens into an erection.

In Peyronie's disease, when the penis becomes erect, the region with the scar tissue doesn't stretch, and the penis bends or becomes disfigured and possibly painful.

In some men, Peyronie's disease comes on gradually and doesn't seem to be related to an injury. Researchers are investigating whether Peyronie's disease might be linked to an inherited trait or certain health conditions.

Minor injury to the penis doesn't always lead to Peyronie's disease. However, various factors can contribute to poor wound healing and scar tissue buildup that might play a role in Peyronie's disease. These include:

• Heredity. If your father or brother has Peyronie's disease, you have an increased risk of the condition.
• Connective tissue disorders. Men who have a connective tissue disorder appear to have an increased risk of developing Peyronie's disease. For example, a number of men who have Peyronie's disease also have a cord-like thickening across the palm that causes the fingers to pull inward (Dupuytren's contracture).
• Age. The prevalence of Peyronie's disease increases with age, especially in men over 55.

Other factors — including certain health conditions, smoking and some types of prostate surgery — might be linked to Peyronie's disease.

Complications of Peyronie's disease might include:

• Inability to have sexual intercourse
• Difficulty achieving or maintaining an erection (erectile dysfunction)
• Anxiety or stress about sexual abilities or the appearance of your penis
• Stress on your relationship with your sexual partner
• Difficulty fathering a child, because intercourse is difficult or impossible