What causes hemorrhoids?
Swelling in the anal or rectal veins causes hemorrhoids. Several factors may cause this swelling, including

• Chronic constipation or diarrhea
• Straining during bowel movements
• Sitting on the toilet for long periods of time
• A lack of fiber in the diet

Another cause of hemorrhoids is the weakening of the connective tissue in the rectum and anus that occurs with age.

Pregnancy can cause hemorrhoids by increasing pressure in the abdomen, which may enlarge the veins in the lower rectum and anus. For most women, hemorrhoids caused by pregnancy disappear after childbirth.