Hemorrhoids (AmE), haemorrhoids (BrE), emerods, or piles are swelling and inflammation of veins in the rectum and anus. The anatomical term "hemorrhoids" technically refers to "'Cushions of tissue filled with blood vessels at the junction of the rectum and the anus." However, the term is popularly used to refer to varicosities of the hemorrhoid tissue. Perianal hematoma are sometimes misdiagnosed and mislabeled as hemorrhoids, when in fact they have different causes and treatments.

Causes

Increased straining during bowel movements caused by constipation or diarrhea may lead to hemorrhoids. It is thus a common condition due to constipation caused by water retention in women experiencing premenstrual syndrome or menstruation.

Hypertension, particularly portal hypertension, can also cause hemorrhoids because of the connections between the portal vein and the vena cava which occur in the rectal wall -- known as portocaval anastomoses.

Obesity can be a factor by increasing rectal vein pressure. Poor muscle tone or poor posture can result in too much pressure on the rectal veins.

Pregnancy may lead to hypertension and increase strain during bowel movements, so hemorrhoids are often associated with pregnancy. Fact: date=March 2009

Cigarette smoking during bowel movements, may worsen hemorrhoid, may lead to severe internal bleeding of veins inside rectum area.

Excessive consumption of alcohol or caffeine can cause hemorrhoids. Both can cause diarrhea. Note that caffeine ingestion increases blood pressure transiently, but is not thought to cause chronic hypertension. Alcohol can also cause alcoholic liver disease leading to portal hypertension.

Symptoms

Many anorectal problems, including fissures, fistulae, abscesses, anal melanoma or irritation and itching, also called pruritus ani, have similar symptoms and are incorrectly referred to as hemorrhoids.

Hemorrhoids are usually not dangerous or life threatening. In most cases, hemorrhoidal symptoms will go away within a few days.

Although many people have hemorrhoids,and hemorroidial radiation, not all experience symptoms. The most common symptom of internal hemorrhoidial radiation is bright red blood covering the feces, on toilet paper, and/or in the toilet bowl. However, an internal hemorrhoid may protrude through the anus outside the body, becoming irritated and painful. This is known as a protruding hemorrhoid.

Symptoms of external hemorrhoids may include painful swelling or a hard lump around the anus that results when a blood clot forms. This condition is known as a thrombosed external hemorrhoid.

In addition, excessive straining, rubbing, or cleaning around the anus may cause irritation with bleeding and/or itching, which may produce a vicious cycle of symptoms. Draining anal mucus, produced by the dentate line may also cause itching.