Edema (swelling) of the foreskin or tearing of the epidermis can result from sexual activity, including masturbation[citation needed].
Paraphimosis is an inability to move the foreskin forward, over the glans. It can result from fluid trapped in a foreskin which is left retracted, perhaps following a medical procedure, or accumulation of fluid in the foreskin because of friction during vigorous sexual activity.
In Peyronie's disease, anomalous scar tissue grows in the soft tissue of the penis, causing curvature. Severe cases can benefit from surgical correction.
A thrombosis can occur during periods of frequent and prolonged sexual activity, especially fellatio. It is usually harmless and self-corrects within a few weeks.
Infection with the herpes virus can occur after sexual contact with an infected carrier; this may lead to the development of herpes sores.
Pudendal nerve entrapment is a condition characterized by pain on sitting and loss of penile (or clitoral) sensation and orgasm. Occasionally there is a total loss of sensation and orgasm. The pudendal nerve can be damaged by narrow, hard bicycle seats and accidents.
Penile fracture can occur if the erect penis is bent excessively. A popping or cracking sound and pain is normally associated with this event. Emergency medical assistance should be obtained. Prompt medical attention lowers likelihood of permanent penile curvature.
In diabetes, peripheral neuropathy can cause tingling in the penile skin and possibly reduced or completely absent sensation. The reduced sensations can lead to injuries for either partner and their absence can make it impossible to have sexual pleasure through stimulation of the penis. Since the problems are caused by permanent nerve damage, preventive treatment through good control of the diabetes is the primary treatment. Some limited recovery may be possible through improved diabetes control.
Erectile dysfunction or impotence is the inability to have and maintain an erection sufficiently firm for satisfactory sexual performance. Diabetes is a leading cause, as is natural aging. A variety of treatments exist, including drugs, such as sildenafil citrate (marketed as Viagra) which works by vasodilation.
Priapism is a painful and potentially harmful medical condition in which the erect penis does not return to its flaccid state. The causative mechanisms are poorly understood but involve complex neurological and vascular factors. Potential complications include ischaemia, thrombosis, and impotence. In serious cases the condition may result in gangrene, which may necessitate amputation. The condition has been associated with a variety of drugs including prostaglandin but not sildenafil (Viagra)
Lymphangiosclerosis is a hardened lymph vessel, although it can feel like a hardened, almost calcified or fibrous, vein. It tends not to share the common blue tint with a vein however. It can be felt as a hardened lump or "vein" even when the penis is flaccid, and is even more prominent during an erection. It is considered a benign physical condition. It is fairly common and can follow a particularly vigorous sexual activity for men and tend to go away if given rest and more gentle care, for example by use of lubricants.
Carcinoma of the penis is rare with a reported rate of 1 person in 100,000 in developed countries. Circumcision is said to protect against this disease but this notion remains controver
