Hemorrhoids (HEM-uh-roids), also called piles, are swollen veins in your anus and lower rectum, similar to varicose veins. Hemorrhoids have a number of causes, although often the cause is unknown. They may result from straining during bowel movements or from the increased pressure on these veins during pregnancy. Hemorrhoids may be located inside the rectum (internal hemorrhoids), or they may develop under the skin around the anus (external hemorrhoids).
Hemorrhoids are very common. Nearly three out of four adults will have hemorrhoids from time to time. Sometimes they don't cause symptoms but at other times they cause itching, discomfort and bleeding.
Occasionally, a clot may form in a hemorrhoid (thrombosed hemorrhoid). These are not dangerous but can be extremely painful and sometimes need to be lanced and drained.
Fortunately, many effective options are available to treat hemorrhoids. Many people can get relief from symptoms with home treatments and lifestyle changes.
Signs and symptoms of hemorrhoids may include:
Hemorrhoid symptoms usually depend on the location.
Internal hemorrhoids. These lie inside the rectum. You usually can't see or feel these hemorrhoids, and they rarely cause discomfort. But straining or irritation when passing stool can damage a hemorrhoid's surface and cause it to bleed.
Occasionally, straining can push an internal hemorrhoid through the anal opening. This is known as a protruding or prolapsed hemorrhoid and can cause pain and irritation.
External hemorrhoids. These are under the skin around your anus. When irritated, external hemorrhoids can itch or bleed.
Thrombosed hemorrhoids. Sometimes blood may pool in an external hemorrhoid and form a clot (thrombus) that can result in severe pain, swelling, inflammation and a hard lump near your anus.