Hemorrhoids (HEM-uh-roids), also called piles, are swollen veins in your anus and lower rectum, similar to varicose veins. Hemorrhoids can develop inside the rectum (internal hemorrhoids) or under the skin around the anus (external hemorrhoids).
Nearly three out of four adults will have hemorrhoids from time to time. Hemorrhoids have a number of causes, but often the cause is unknown.
Signs and symptoms of hemorrhoids usually depend on the type of hemorrhoid.
These are under the skin around your anus. Signs and symptoms might include:
- Itching or irritation in your anal region
- Pain or discomfort
- Swelling around your anus
Internal hemorrhoids lie inside the rectum. You usually can’t see or feel them, and they rarely cause discomfort. But straining or irritation when passing stool can cause:
- Painless bleeding during bowel movements. You might notice small amounts of bright red blood on your toilet tissue or in the toilet.
- A hemorrhoid to push through the anal opening (prolapsed or protruding hemorrhoid), resulting in pain and irritation.
The veins around your anus tend to stretch under pressure and may bulge or swell. Hemorrhoids can develop from increased pressure in the lower rectum due to:
- Straining during bowel movements
- Sitting for long periods of time on the toilet
- Having chronic diarrhea or constipation
- Being obese
- Being pregnant
- Having anal intercourse
- Eating a low-fiber diet
- Regular heavy lifting
Complications of hemorrhoids are rare but include:
- Anemia. Rarely, chronic blood loss from hemorrhoids may cause anemia, in which you don’t have enough healthy red blood cells to carry oxygen to your cells.
- Strangulated hemorrhoid. If the blood supply to an internal hemorrhoid is cut off, the hemorrhoid may be “strangulated,” which can cause extreme pain.
- Blood clot. Occasionally, a clot can form in a hemorrhoid (thrombosed hemorrhoid). Although not dangerous, it can be extremely painful and sometimes needs to be lanced and drained.