Hemorrhoids are present in everyone. They are contained with arteries supplying blood to the anal canal which descend into the canal from the rectum above. This network of arteries communicate with each other around the anal canal. Because these are arteries, hemorrhoidal blood vessels contain arterial blood. For this reason, when hemorrhoids are bleeding it is bright red (arterial blood) rather than dark red (venous blood). The blood vessels that supply the hemorrhoid vessels pass through the supporting tissue of the hemorrhoid cushions. It is only when the hemorrhoidal cushions enlarge that hemorrhoids can cause problems and be considered abnormal or a disease.
There are two types of hemorrhoids: external and internal, which refer to their location.
- External (outside) hemorrhoids develop near the anus and are covered by very sensitive skin. These are usually painless. However, if a blood clot (thrombosis) develops in an external hemorrhoid, it becomes a painful, hard lump. The external hemorrhoid may bleed if it ruptures.
- Internal (inside) hemorrhoids develop within the anus beneath the lining. Painless bleeding and protrusion during bowel movements are the most common symptom. However, an internal hemorrhoid can cause severe pain if it is completely “prolapsed” – protrudes from the anal opening and cannot be pushed back inside.
While there are predictors and one fact known, it is not clearly known why hemorrhoids become become enlarged. We do know consistent conditions that will exist when hemorrhoids appear. They usually include
- Lack of fiber
- Prolonged sitting on the toilet
- Chronic straining
- Tumors in the pelvis area
One theory of causation is the pulling force of stool passing through the anal canal. This force drags the hemorrhoidal cushion downwards causing deterioration of the anal canal. With time, the hemorrhoidal tissue loses its mooring and slides down into the anal canal.
One fact that is known about enlarged hemorrhoids. They form when the pressure pressure is elevated in the anal sphincter. This muscle surrounds the anal canal and the hemorrhoids. It is not known, however, if this pressure happens and causes the enlarged hemorrhoids or if it is the result of hemorrhoids.
In addition to there being two different types of hemorrhoids, there are also different levels of severity.
- First-degree: Hemorrhoids that bleed but do not protrude into the anal canal.
- Second-degree: Hemorrhoids that protrude and retract on their own (with or without bleeding).
- Third-degree: Hemorrhoids that protrude and can be pushed back in by a finger.
- Fourth-degree: Hemorrhoids that protrude, but cannot be pushed back in. Fourth-degree hemorrhoids also include hemorrhoids that contain blood clots or pull the lining of the rectum through the anus.
External hemorrhoids are easier to diagnosis as they can generally be seen or felt. Internal hemorrhoids need an anal examination. If any of the symptoms exist, there should be an examination by a doctor to rule out other GI conditions that have similar symptoms.