Risk factors

Excessive straining at bowel movements.
Heavy weight lifting.
Diet high in processed food and low in fiber, which tends to cause constipation.
Sedentary lifestyle with no exercise.
Any condition which increases intra-abdominal (in the abdomen) pressure
- Childbirth
- Chronic cough
- Obesity
During pregnancy, there can be formation of piles (hemorrhoids)due to compression of the hemorrhoidal veins, which can be due to:
- pressure as a result of enlarged uterus carrying the baby.
- relaxing effect of progesterone on the smooth muscle of the vein, leading to dilatation.
- increase blood flow of the pelvic region.
Straining at urination due to enlarged prostrate in males or urethral stricture (narrowing of the urinary opening).
Chronic constipation, prolonged sitting, anal infection.
Cancer of rectum, causes compression or thrombosis (blood clot) in the hemorrhoidal vein giving rise to piles (hemorrhoids).
Loss of muscle tone in the rectum due to old age and after rectal surgery.
Hereditary: The problem of piles (especially internal hemorrhoids) may run in the families.