An absolutely straight penis is unusual – most have a slight curve when erect. But this should not be more than about 25° from straight, like a banana. If your penis bends more than this, you might have Peyronie’s disease. It is also quite normal and harmless for the penis to have a slight twist (usually anticlockwise).
A condition called Peyronie's disease, in which the penis becomes crooked when it is erect, occasionally develops in men. This can make sexual intercourse difficult, if not impossible. It is estimated that about 1 in 100 men has Peyronie’s disease.
Peyronie’s disease most commonly occurs in men aged 50–60, but it can occur in young men and in old age. The cause is thickening of the fibrous tissue in the penis on one side. This means that, during an erection, one side of the penis cannot lengthen, and the penis will bend. The direction of the bend depends on the position of the thickening (which can often be felt as a lump or lumps when the penis is limp).
● If the thickening is on the glans (supara) of the penis , the erection tends to curve upwards; this is the most common type.
● If the thickening is on either side, the penis will bend towards the side that is thickened.
● If there is thickening on both sides, the penis may develop an hour-glass shape, but this is unusual.
You may be able to feel the thickened area; it feels like a hard piece of toffee.
● What causes Peyronie's disease? No one knows why the thickening occurs, but it is not a cancerous condition, nor is it the result of sexually transmitted disease or of any odd previous sexual practices. It is more common in smokers. There seems to be a link with some other conditions. For example, men with Peyronie’s disease are quite likely to have Dupuytren’s contracture, a thickening of fibrous tissue in the palm of the hand. They are also quite likely to have raised blood pressure; some doctors think that the blood pressure itself might be responsible for the penis problem, while others blame the drugs used to treat blood pressure (particularly beta-blockers).
● Treatment — There is no need to feel embarrassed about discussing the problem with your family doctor, because doctors are very familiar with the condition. It may be difficult for your doctor to assess how severe the problem is, because the curvature shows only when the penis is erect. If you have a digital or instant-picture camera, take a photograph of your erect penis and show it to your doctor. Treatments that do not involve surgery are recommended during the first 12 months, while the scarring is developing. After that, when the scarring has finished forming, surgery is often the best option. If it is only mild and does not cause any inconvenience, no treatment is necessary.
Best of luck,