Peyronie's disease is a connective tissue disorder that affects 5-10% of all men, where fibrous scar tissue develops inside the soft tissue of the penis.  This scar tissue leads to curved, and many times painful erections.  This can make having sex, or maintaining an erection difficult.  Similarly, this change in penile function coupled with a change in the “look” of the penis can lead to unwanted stress and anxiety in a man’s sex life.  For some men, this disorder resolves on its own but for most it will more likely stay the same or worsen.  A slight curve in the penis is not necessarily a cause for concern – but if it is or becomes significant, this should be evaluated by a doctor.