While most penises show some form of bent or curved appearance, if the penis is abnormally bent upon erection, it is a sign of Peyronie's disease. This abnormal curvature can be towards the south or north or even sideways. It is caused due to a scar tissue (called 'plaque') at some point of the shaft of the penis. What causes this? Well, trauma or injury are obvious candidates. But not all curved penises are caused by being hit. There is no clear-cut answer yet to what causes a curved penis. Some studies have linked the condition with the family history of the same. Tissue changes that come with age can also be a risk factor, leaving men aged 40 + more vulnerable.
While sometimes, it may point to something serious like a urethral obstruction (caused by blockages in the urethra), a curved penis is not a form of STI or a symptom of cancer! Injuries during prolonged cases of rough sex or masturbation can be culprits in some cases. But routine masturbation can rarely lead to a fractured or a broken penis, as is often made out!
In most cases where a curved penis hasn't reached the levels of being very painful, it has its own unique advantages for sex. The male can derive added pleasure from the act and so can the female. The curvature allows the man to thrust with a grinding rhythm thus adding to his pleasure. At the same time, the curvature makes it easier for the penis to rub against the G-Spot or the vaginal walls thus adding to the woman's pleasure too.
While some cases of bent penis may result in a lot of pain, it doesn't mean there's nothing one can do about it. Medication, topical injections, shock therapy, etc are common methods of treatment. In more serious cases, surgery may be required.
As said earlier, a slight curve or bent in a penis is common. But it is not equally common for such a curve to reach painful proportions. There are no final, official numbers as to the number of men with Peyronie’s disease, but rough estimates can be given. Depending on various studies, the prevalence rates of Peyronie's disease are anywhere between 0.5 percent to 9 percent of men in the USA.