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Hemorrhoids
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Hemorrhoids are not something you develop: they are a normal structure that everyone has. They are vascular cushions located in the submucosa of the anal canal, that is, in the layer just beneath the inner lining. They are made of loose connective tissue, smooth muscle and blood vessels.
They serve a purpose. They are thought to help with fecal continence, meaning keeping anything from leaking out, by adding bulk to the anal canal. During straining they engorge, or fill with blood, and that leaves the anus completely closed. A padded seal that is already there and fills with blood when you strain, closing off the passage.
What people call having hemorrhoids is hemorrhoidal disease: when those cushions become a problem. It happens when something impedes venous return, the outflow of blood through the veins of the area, and the cushions then grow larger than they should.
In brief
Hemorrhoids are vascular cushions that everyone has in the submucosa of the anal canal, made of loose connective tissue, smooth muscle and blood vessels.
They are thought to help with fecal continence by adding bulk to the anal canal, and during straining they engorge and close the anus completely.
A padded seal that is already there and fills with blood when you strain, closing off the passage.
Hemorrhoidal disease develops when venous return from those vessels falls and the cushions enlarge abnormally.
Sources (2)
- National Center for Biotechnology Information, StatPearls PublishingInternal Hemorrhoid, StatPearlsPublished
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthDefinition & Facts of Hemorrhoids, NIDDKPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated