What Is It?

A hemorrhoid is a bulging, distended vein in the area around the anus, the opening through which stool passes. This happens when pressure in the abdomen increases, causing blood to back up inside blood vessels, making them bulge and stretch out of shape.

In most cases, the increase in abdominal pressure that triggers hemorrhoids is related to one or more of the following:

• Repeated straining to have a bowel movement, especially in people who suffer from frequent constipation

• The pressure of the fetus in pregnant women

• Repeated episodes of diarrhea

• Obesity

• Work that requires prolonged standing (traffic officer, waitress, cashier), sitting (truck driver) or heavy lifting (packing clerk, furniture mover)

• Cirrhosis of the liver, in rare cases

Internal hemorrhoids, which develop inside the passageway of the anus, are usually painless, although they sometimes cause vague discomfort and minimal bleeding if a hard stool rubs against them during a bowel movement. Internal hemorrhoids also may protrude (prolapse) outside the anus, where they appear as small, grape-like masses. These can be painful.

External hemorrhoids, which develop around the rim of the anus, are often fairly painful, because the skin around them is very sensitive. External hemorrhoids sometimes rupture and bleed. When an external hemorrhoid becomes filled with a blood clot, it typically appears as a firm swelling or lump around the rim of the anus.

Hemorrhoids are a very common health problem, affecting about 4% of Americans at any one time. They are most common in men and women aged 45 to 65. . Because the tendency to develop hemorrhoids seems to run in families, doctors believe that at least part of the risk for hemorrhoids is genetic (inherited). You are more likely to develop hemorrhoids if you eat a low-fiber diet and don't get enough exercise, which can lead to repeated episodes of constipation and straining to have bowel movements.

Symptoms

Symptoms of hemorrhoids include:

• Bright red blood on the toilet paper after having a bowel movement, especially if the stool was very hard or very large; blood also may streak the surface of the stool, or lightly color the water inside the toilet bowl

• A vague ache in the anus after having a bowel movement

• For a prolapsed hemorrhoid, a soft, grape-like mass protruding from the anus that may be itchy or painful or may leak a watery fluid or mucus. In some cases, you can gently press the prolapsed hemorrhoid back into the anus with your fingertips.

• For an external hemorrhoid, a painful bulge or firm lump around the rim of the anus. The lump may have a blue or purple tint.