What are hemorrhoids?
Although hemorrhoids will be noticed only if they cause discomfort, everybody has them. As they contribute to the fine adjustment of anal closure, hemorrhoids play a role in stool control.
Hemorrhoids consist of three major vascular pads arranged in a ring around the anal canal. It is common to distinguish between external and internal hemorrhoids
, which are classified anatomically on the basis of their location (see figure 1).
Internal hemorrhoids help together with the anal sphincters muscle to regulate defecation. They become engorged with blood and expand – like a soaked sponge – thus causing closure of the anal canal. Hemorrhoids thus contribute to 15 to 20 percent of the anal closure pressure at rest. During a bowel movement, blood from the vascular cushions is pressed into deeper veins – the "sponge" collapses and clears the way for bowel content.
If the blood pressure in the hemorrhoidal plexus is permanently elevated, the hemorrhoids will become disproportionately enlarged. This may result in hemorrhoidal disease, which is associated with unpleasant symptoms in those affected.
Hemorrhoids is just another word for piles.
Internal hemorrhoids help together with the anal sphincters muscle to regulate defecation. They become engorged with blood and expand – like a soaked sponge – thus causing closure of the anal canal. Hemorrhoids thus contribute to 15 to 20 percent of the anal closure pressure at rest. During a bowel movement, blood from the vascular cushions is pressed into deeper veins – the "sponge" collapses and clears the way for bowel content.
If the blood pressure in the hemorrhoidal plexus is permanently elevated, the hemorrhoids will become disproportionately enlarged. This may result in hemorrhoidal disease, which is associated with unpleasant symptoms in those affected.
Fig. 1: Hemorrhoids, normal condition.
(1) rectum,
(2) hemorrhoidal plexus,
(3) dentate line,
(4) internal anal sphincter muscle,
(5) external anal sphincter,
(6) pelvic floor muscles,
(7) anoderm,
(8) perianal vein.
