What are hemorrhoids?

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    Last Updated: May 16, 2025

    Hemorrhoids are swollen blood vessels located in the anal canal or around the anus, resulting from the enlargement of anal cushions that help control bowel movements. They are fairly common and generally not harmful but can cause discomfort.

    Hemorrhoids are swollen blood vessels within the anal canal/rectum (internal hemorrhoids) or around the opening of the anus (external hemorrhoids). Hemorrhoids result from the pathological enlargement of anal cushions. Anal cushions are a part of anal anatomy that help maintain continence (the ability to control bowel movements) by filling with blood to seal the rectum, and draining during defecation. If this filling and draining process isn’t working properly, they can become enlarged and cause symptoms. Hemorrhoids are generally not harmful, apart from causing discomfort.[1]

    Hemorrhoids are a common condition, with a U.S. survey finding a prevalence of 4.4% in the general public. However, some research reports rates of up to 40%.[2][3] Hemorrhoids affect both sexes equally and prevalence peaks between ages 45 and 65.[2] It’s suggested that by age 50, roughly half of people will have experienced hemorrhoids at some point in their life.[4]