hemorrhoids (hĕmˈəroidz) [key] or piles, dilatations of the veins about the anus (external hemorrhoids) or those higher up inside it (internal hemorrhoids). They appear as small, rounded, purplish tumors, often complicated by inflammation, clotting, and bleeding. Hemorrhoids are very common phenomena and are brought about by factors that produce venous congestion, such as constipation, diarrhea, or pregnancy. In some instances, the pain from inflamed hemorrhoids can be intense, and the bleeding so profuse as to pose the threat of anemia. Hemorrhoids that are uncomplicated or bleed only slightly at infrequent intervals do not require specific treatment except to improve the condition that may be causing them, such as constipation. Hemorrhoids that are very painful or bleed excessively are treated by warm baths and suppositories and, if necessary, by injection, laser surgery, or traditional surgery.