Hemorrhoids are swollen veins fed by arteries around the anus and in the anal canal. The cause is unknown though the most commonly associated condition is pregnancy. The symptoms caused by hemorrhoids will depend on whether the hemorrhoid is internal or external. Internal hemorrhoids are swollen veins beneath the lining of the lower rectum and upper anal canal mucosa. Since the swollen veins are underneath this lining which has few nerve endings the most common symptoms are bleeding and/or tissue protruding, usually with bowel movements.

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External hemorrhoids are inflamed veins beneath the skin of the anus. The skin extends up inside for less than one-half inch. The anal skin is extremely sensitive thus inflamed veins may cause pain, itching, swelling and occasionally bleeding. Occasionally external hemorrhoids will clot or thrombose. This causes sudden very intense pain which will often cause a person to seek medical attention.