Medical Specialties: Family practice, Internal medicine

Clinical Definition

Hemorrhoids are dilated vascular structures under the rectal mucosa. Hemorrhoids may develop outside of the external anal sphincter or inside the anal canal. They are often due to increased pressure on the anorectal area. Increased pressure may be due to constipation and straining during bowel movements.  

In Our Own Words

Very common among people in the 45 – 65 age group, hemorrhoids are enlarged veins in or around the anus. They are often harmless except for the itching and perhaps some bright red blood on the toilet paper; but they can be the source of a variety of problems.


Similar to varicose veins, hemorrhoids often occur because of an increase in pressure on the blood vessels. Straining during a bowel movement, which is often due to constipation, can cause increased pressure. The increased pressure causes the veins to swell and stretch, which leads to hemorrhoids. Hemorrhoids can develop externally, occurring under the skin around the anus. They can also develop internally, inside the anus.

Relevant Conditions
  • Constipation
  • Anal fissures
Common Types
  • Internal
  • External
Side Effects
  • Lump in or outside the anus
  • Anal itching
  • Blood in the stool
Share this article
  • The Merck Manual. “Hemorrhoids.” Last review/revision July 2012. http://www.merckmanuals.com. Accessed November 2013.
  • Harvard Medical Center. “Hemorrhoids and What to do About Them.” http://www.health.harvard.edu. Accessed November 2013.
  • The Ohio State University Wexner Medical Center. “Hemorrhoids.” http://medicalcenter.osu.edu. Accessed November 2013.
Keep Reading

Investigate your bodys signs and signals.
Try Symptom Checker