Hemorrhoids are collections of inflamed tissue in the anal canal. They contain blood vessels, support tissue, muscle, and elastic fibers . Piles are collections of tissue and vein that become inflamed and swollen. The size of piles can vary, and they are found inside or outside the anus. Piles occur due to chronic constipation, chronic diarrhea, lifting heavy weights, pregnancy, or straining when passing a stool. A doctor can usually diagnose piles on examination. Hemorrhoids are graded on a scale from I to IV. At grades III or IV, surgery may be necessary. Get the Best Piles Treatment in Delhi . Haemorrhoids are usually caused by straining during bowel movements, obesity or pregnancy. Discomfort is a common symptom, especially during bowel movements or when sitting. Other symptoms include itching and bleeding.