Penile edema is painless, non-tender swelling of the penis. The swelling is caused by lymphatic vessel inflammation causing obstruction and fibrosis.

Acute edema is caused by angioedema, allergic contact dermatitis, bacterial infections, herpes simplex virus (HSV) and other STDs, parenteral fluid overload, or peritonitis. Chronic edema may be linked to congenital lymphatic abnormalities, recurrent erysipelas, neoplasms, radiation, or injection of a foreign substance.

If hemorrhage is present, there may be a tear the tunica albuginea, in which case emergency surgery and repair is indicated.

Genital lymphedema is common in countries with high prevalence of filariasis. Filariasis is endemic in over 80 countries in Africa, Asia, South and Central America, and the Pacific Islands. More than two-thirds of infected people live in India or Africa.