Hemorrhoids , 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.
Symptoms
Signs and symptoms of hemorrhoids usually depend on the type of hemorrhoid.
External hemorrhoids
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
Bleeding
Internal hemorrhoids
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.
Thrombosed hemorrhoids
If blood pools in an external hemorrhoid and forms a clot (thrombus), it can result in:
Severe pain
Swelling
Inflammation
A hard lump near your anus
Causes
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
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