Hemorrhoids are swollen, inflamed anal or rectal veins. They're essentially varicose veins around the anus or lower rectum.

About 75% of people in the U.S. will have hemorrhoids at some point in their lives -- most commonly between the ages of 45 and 65.

Hemorrhoid symptoms (which can include pain, itching, swelling, and bleeding during bowel movements), usually go away within a few days; they are not considered dangerous. However, if you have rectal bleeding or severe pain, you should see a doctor to rule out more serious conditions.

Chronic constipation and chronic diarrhea are both risk factors for hemorrhoids.

Spending a long time on the toilet can contribute to hemorrhoids. Other contributing factors include age, straining during bowel movements, and overuse of laxatives or enemas.

Heavy lifting, or any activity that causes you to strain or increases pressure on the veins of your rectum or anus, can cause hemorrhoids.

Pregnant women more often get hemorrhoids because of a number of factors, including increased pressure in their abdomen, hormonal changes, and constipation. Hemorrhoid symptoms in pregnancy usually disappear after childbirth.

If your parents had hemorrhoids, you are more likely to get them than someone with no family history of hemorrhoids.

The two types of hemorrhoids are internal and external. External hemorrhoids are found under the skin around the anus, and they can become painful and itchy; internal hemorrhoids are usually painless, but they can protrude outside the body and become painful and itchy as well.

Simple diet and lifestyle changes can reduce your chances of getting hemorrhoids. Dietary fiber improves digestion and can help prevent constipation, reducing the strain and pressure on your rectum when passing stools. Proper hydration and regular exercise also can improve digestion and reduce rectal straining.

Warm soaks can help relieve pain of hemorrhoids, applying ice packs can reduce swelling, and witch hazel can ease the itching. Witch hazel can be applied directly with cotton swabs or as an ingredient in a cream or ointment. Other helpful over-the-counter treatments include corticosteroid creams, hemorrhoid creams, acetaminophen, ibuprofen, and aspirin.

Constipation can aggravate hemorrhoids. The American Academy of Family Physicians' web site states that "when you feel the need to have a bowel movement, don't wait too long to use the bathroom."

Rubber band ligation is an effective treatment for internal hemorrhoids. A doctor places a small rubber band around the hemorrhoid to cut off its blood supply, and after a few days, it falls off. Internal hemorrhoids also can be treated and destroyed with chemical injections, and doctors may use surgical staples used as part of a procedure to cut away internal hemorrhoidal tissue or to shrink external hemorrhoids. 

Other treatments include the use of heat or electrotherapy to resolve the hemorrhoid. Prolapsed or large hemorrhoids may need to be surgically removed (hemorrhoidectomy).

Hemorrhoids have no known relationship to colorectal cancer and are not a risk factor. However, the symptoms of hemorrhoids can be similar to those of colorectal cancer, so if you have symptoms such as rectal bleeding, you should see a doctor.

"Piles" is another term used for hemorrhoids. It comes from the Latin "pila," meaning "ball." The term "hemorrhoid" comes from the Greek "haema" (blood) and "rhoos" (flowing). In the Middle Ages, they were known as St. Fiacre's curse. Hemorrhoids may have been treated as early as 2250 B.C. in Babylon.