Hemorrhoids are swollen blood vessels at the opening of the anus or at the lower end of the bowels. It’s also possible to inherit a tendency to develop hemorrhoids. Hemorrhoids are more likely as you get older because the tissues that support the veins in your rectum and anus can weaken and stretch with aging.
The causes of hemorrhoids are not limited to the following: straining during bowel movements, sitting for long periods of time on the toilets, chronic diarrhea or constipation and obesity or being overweight.
Excess weight, especially in the abdomen and pelvis, may increase pressure on pelvic veins. Pregnancy [during pregnancy increase blood flow to the pelvis and relax supportive tissues while the growing fetus causes increased pressure on blood vessels. During labor, hemorrhoids may develop because of the intense pressure on the anal area while pushing to deliver the baby].
Medical conditions: For example, long-term heart and liver disease may cause blood to pool in the abdomen and pelvic area, enlarging the veins.