What are hemorrhoids? Hemorrhoids are enlarged, bulging veins in the anus or rectum. They are called external hemorrhoids if they occur outside the anus, or internal hemorrhoids if they are located inside the anus. Hemorrhoids are extremely common, and the risk of developing hemorrhoids increases with age. They are also common in pregnant women and in women who have recently given birth. These distended veins are usually caused by straining that occurs during a bowel movement. In rare cases, hemorrhoids can be a manifestation of liver disease or malformations of the venous system. External hemorrhoids can be painful, particularly when sitting and during a bowel movement. In addition, a blood clot called a thrombosis can occur along with external hemorrhoids. A thrombosed hemorrhoid may bleed, swell painfully, or form a hard lump. An internal hemorrhoid can protrude or prolapse from the anus. In some cases, hemorrhoids can lead to more serious complications. Most hemorrhoids can be treated at home, usually through lifestyle and diet changes. A diet high in fiber and plenty of fluids can make bowel movements easier and less likely to produce straining. Over-the-counter creams and ointments can help reduce the swelling, itching and pain of hemorrhoids. Severe hemorrhoids can be treated surgically if they do not respond to other treatment. Seek prompt medical care if you are being treated for hemorrhoids, but your symptoms persist, recur, or cause you concern.