Hemorrhoids

Alternative names:

lump in the rectum; piles; rectal lump

Definition:

Enlarged veins in the lower portion of the rectum or anus.

Causes, incidence, and risk factors:

Hemorrhoids are caused by increased pressure in the veins of the anus. The most common cause is straining at bowel movements. Constipation, prolonged sitting, and anal infection are contributing factors. Internal hemorrhoids occur near the beginning of the anal canal, and external hemorrhoids occur at the anal opening. Hemorrhoids also sometimes protrude outside the anus. They are very common, especially during pregnancy and after childbirth. The incidence is 2 out of 1000 people.