Hemorrhoids are caused primarily by increased pressure in the lower rectum, which leads to swelling and bulging of veins around the anus and rectum. Key factors that cause or contribute to this increased pressure include:
- Straining during bowel movements, often due to constipation or hard stools.
- Sitting for long periods, especially on the toilet.
- Chronic diarrhea or constipation.
- Pregnancy, where the growing uterus presses on pelvic veins.
- Aging, which weakens the connective tissues supporting the veins.
- Obesity, which increases pressure on pelvic veins.
- Heavy lifting or activities that increase abdominal pressure.
- Low-fiber diet, which can lead to constipation and straining.
- Anal intercourse may also contribute in some cases.
These factors interfere with normal blood flow, causing blood to pool and veins to stretch, swell, or bulge, resulting in hemorrhoids
. Additionally, some studies suggest that people with hemorrhoids may have a higher resting anal canal tone, meaning the muscles in the anal canal are tighter than average, which can exacerbate the problem
. In summary, hemorrhoids develop due to increased pressure and weakened support in the anal and rectal veins, often linked to bowel habits, pregnancy, aging, and lifestyle factors.
