Some men have a slight natural curve in their penis, which is nothing to worry about. However, if you are experiencing pain, you may be suffering from Peyronnie's disease. Its exact cause is unknown, but it often runs its course without requiring treatment. There is some evidence that Peyronie's disease is an autoimmune disorder and perhaps hereditary, but the majority of cases are probably the result of trauma. The initial accident may be minor, but as the injury heals, scar tissue forms and deformation results. Over time, the curvature often becomes less severe but seldom straightens completely.

In the past, urologists have battled Peyronie's with surgery, vitamin E, radiation therapy, ultrasound, aminobenzoate potassium and steroid and collagenase injections, among other treatments. But it's not clear whether the non-surgical methods corrected the condition or whether it was simply a case of "spontaneous remission," as often happens. In severe cases, surgery can straighten (and consequently shorten) the penis. In the most serious cases, doctors can perform a penile implant. Our advice: See if the situation improves over time. If it doesn't, or if you're having trouble having intercourse, check with a specialist. See a doctor immediately if you are in pain.