Hemorrhoid, also called piles or rectal lumps, is a medical condition that occurs when veins in the lower portion of the anus or rectum swell and become painful. Based on the location of the lump, Hemorrhoids can be internal or external. External ones occur at the opening of the anus and cause pain, swelling and irritation. Internal Hemorrhoids develop inside the rectum and because the area has less pain receptors, they are comparatively less painful. When irritated, internal Hemorrhoids can cause bleeding. Sometimes, both the internal and external types can occur together.