Question: What is (are) Hemorrhoids ?
Answer: Hemorrhoids are swollen and inflamed veins around the anus or in the lower rectum. The rectum is the last part of the large intestine leading to the anus. The anus is the opening at the end of the digestive tract where bowel contents leave the body. External hemorrhoids are located under the skin around the anus. Internal hemorrhoids develop in the lower rectum. Internal hemorrhoids may protrude, or prolapse, through the anus. Most prolapsed hemorrhoids shrink back inside the rectum on their own. Severely prolapsed hemorrhoids may protrude permanently and require treatment.
Source: NIDDK