Peyronie's disease is a disorder affecting the penis that can cause:

Not all of these features are necessarily present but typically, a man would first notice a tender lump in the penis, which might later be followed by bending of the penis when erect, sometimes at very odd angles. The flaccid penis is not usually deformed. It is important to remember that a degree of upward (towards the head) angulation of the erect penis is quite normal and not a feature of Peyronie's disease. Noticing a lump in the penis can be a frightening experience. Men are often concerned that they have developed a cancer. Cancer within the penile shaft is very rare indeed, while Peyronie's disease is by far the most common cause of such lumps. If you find a lump, it is important to seek prompt medical advice, but you should not be too fearful that a serious cause will be found.
The penis consists of basically three cylinders, covered by several sheaths of tissue and, finally, by skin. Running the length of each side of the penis are spongy cylindrical structures called the corpora cavernosa. These form the erectile tissue that becomes engorged with blood during erection, acting like the inner tube of a tyre. They are surrounded by the tunica albuginea, a tough, inelastic, fibrous sheath, which might be compared with the tyre itself. When the penis becomes erect, the inner tubes (corpora cavernosa) inflate, filling the space within the tyre (tunica albuginea), making it more rigid. In Peyronie's disease, tough, fibrous plaques spontaneously appear within the tunica albuginea, and are felt as tender lumps. When the penis becomes erect, it inflates unevenly and tends to bend around the plaque, causing the characteristic deformed appearance of Peyronie's disease. One in three men with Peyronie’s have pain or penile bending when erect as their principal symptom. Experts are not certain why some men get Peyronie's disease and others do not. Several factors might be involved, including:
Genetics: Occasionally the disease has a tendency to run in certain families (inherited or genetic predisposition), but this is not common.
Injury: Peyronie's disease is more common after injury to the penis, such as penile fracture or forceful bending of the erect penis. It also occurs more frequently in men that give injections into the penis for the treatment of erectile dysfunction (impotence).
Circulatory disorders: more men with Peyronie's disease seem to be affected by high blood pressure (hypertension) and hardening of the arteries (atherosclerosis), so these conditions might possibly be involved in its development.
Diabetes:This is more common in men with Peyronie's disease. As a result diabetes might also be involved in its development.
Peyronie's disease occurs at any time from adolescence onwards, but most commonly in men aged 40 to 60 years. It affects around 1 in a 100 (0.4 to 1.0 per cent) of the middle-aged male population, but some experts suggest up to 4 per cent of men aged over the age of 40 may suffer from it. The disease causes very variable degrees of deformity and inconvenience.Some men are barely troubled by it, while others find sexual intercourse physically impossible. Many men will not require treatment, but all should seek prompt medical advice.
The symptoms:
A lump within the shaft of the penis: this can slowly develop over several months and frequently takes 12 to 18 months to reach its full extent.
Pain in the shaft of the penis: two-thirds of men with Peyronie's disease will experience pain in the penis. In most cases, it will gradually settle down and disappear without treatment in a few months.
Abnormal angulation of the erect penis ('bent' penis): during the 12 to 18 months that the plaque or lump is developing, the deformity of the erect penis can change - 30 to 40 per cent get worse, 10 to 20 per cent get better and 50 per cent remain the same.Some men will develop varying degrees of erectile dysfunction (impotence) as a consequence of Peyronie's disease. This can vary from a complete inability to attain and maintain an erection adequate for satisfactory sexual experience to a slight reduction in penile rigidity. Some men report a tendency for the penis to buckle around the lump during sex. The frequency of this problem has been reported as between 4 and 80 per cent, although experience suggests that the true rate is towards the lower end of this range.Peyronie's disease is diagnosed on the basis of the history (how the problem has developed, as you describe it to your doctor) and examination (what the doctor can see and feel). Between 10 and 25 per cent of men with Peyronie's disease have Dupuytren's contracture, a claw-like deformity in which the little finger, the ring finger and, sometimes, other fingers bend over towards the palm of the hand. No special investigations are needed and biopsy (surgically removing a piece of the lump for examination under a microscope) is only needed for rapidly enlarging lumps that are not developing in the usual manner.
Ultrasound scanning can be used to assess the exact size and position of the lump, but is rarely necessary. Although extremely rare, sarcoma of the penis (a form of cancer) can present in a similar way. Your doctor will consider this if the lump enlarges very rapidly or develops in an unusual manner. If you think that you might have Peyronie's disease, you should seek medical advice. If the problem has been present for a long time, is not changing, and is not causing you much trouble, the doctor might recommend no treatment and simply ask you to return if the condition starts to worsen. If the problem has been present for a long time and is causing you sexual difficulties (such as impotence, difficulty with penetration, or pain during sex for either partner), they may refer you to a urologist. You might need surgical treatment to correct the deformity. It is unwise to seek surgical treatment solely for cosmetic reasons. If the problem has recently developed, particularly if the lump is continuing to develop or is painful, the doctor may consider offering drug treatment.
Although Peyronie's disease is not that uncommon, men do not frequently ask about it so some GPs might be unfamiliar with treatment options. It is reasonable to request referral or to refer yourself to a GUM clinic, if you are unhappy with the explanation and advice you have received.There is nothing you can do to prevent the development of Peyronie's disease after it has appeared. However, avoiding penile trauma might prevent it. Men who are injecting into the penis to treat erectile dysfunction might reduce their risk of developing Peyronie's disease by careful injection technique and by varying the site of injections. This advice is usually given when patients are first taught to use injections.
Unani system of medicines has a very successful track record of treating the patients of this disease.
Peyronie's disease runs a very variable course. Many men with Peyronie's disease will not require or desire treatment, and will enjoy very satisfactory sex with their rather unusually shaped penis.Men who have had Peyronie's disease are more likely to have a further episode in the future than the general population. Nothing is proven to prevent a recurrence.