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Hemorrhoid is a topic covered in the 5-Minute Emergency Consult.

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  • General:
    • Normal venous sinusoids of the distal rectum and proximal anal canal
    • Normal vascular cushions of anal canal that contribute to anal continence
    • Arteriovenous shunt system exists at the level of the internal hemorrhoids that accounts for the bright red blood per rectum
  • When the hemorrhoids become symptomatic, hemorrhoid disease develops.
  • Do not cause pain unless thrombosed or strangulated
  • Discrete masses of thick submucosa contain:
    • Blood vessels
    • Smooth muscle
    • Elastic and connective tissue
  • Sliding down of part of anal canal lining
  • External hemorrhoids:
    • Vessels situated below dentate line
    • Covered by skin/anoderm
    • Drain to internal iliac veins
  • Internal hemorrhoids:
    • Submucosal vessels above dentate lines
    • Drain to portal system
    • Usually at left lateral, right posterolateral, and right anterolateral positions
    • Grade 1: Painless, bleeding
    • Grade 2: Prolapse with bowel movement (BM), spontaneously reduce
    • Grade 3: Prolapse with BM, require manual reduction
    • Grade 4: Chronically prolapsed, not reducible


  • Exact cause unknown
  • Gravitational forces and abdominal pressure cause distention of the sinusoids
  • Associated with straining and irregular bowel habits:
    • Hard, bulky stools or diarrhea cause tenesmus/straining.
    • Push anal cushions out of anal canal
    • Weaken submucosal tissue leading to prolapse
  • Higher resting anal pressures:
    • Erect posture
  • Heredity:
    • Absence of valves in veins
  • Increased intra-abdominal pressure:
    • Ascites
    • Pregnancy
  • Portal hypertension

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Rosen, Peter, et al., editors. "Hemorrhoid." 5-Minute Emergency Consult, 5th ed., Lippincott Williams & Wilkins, 2016. Emergency Central, emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307226/all/Hemorrhoid.
Hemorrhoid. In: Rosen P, Shayne P, Barkin AZ, et al, eds. 5-Minute Emergency Consult. 5th ed. Lippincott Williams & Wilkins; 2016. https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307226/all/Hemorrhoid. Accessed April 25, 2019.
Hemorrhoid. (2016). In Rosen, P., Shayne, P., Barkin, A. Z., Wolfe, R. E., Hayden, S. R., Barkin, R. M., & Schaider, J. J. (Eds.), 5-Minute Emergency Consult. Available from https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307226/all/Hemorrhoid
Hemorrhoid [Internet]. In: Rosen P, Shayne P, Barkin AZ, Wolfe RE, Hayden SR, Barkin RM, Schaider JJ, editors. 5-Minute Emergency Consult. Lippincott Williams & Wilkins; 2016. [cited 2019 April 25]. Available from: https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307226/all/Hemorrhoid.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Hemorrhoid ID - 307226 ED - Rosen,Peter, ED - Shayne,Philip, ED - Barkin,Adam Z, ED - Wolfe,Richard E, ED - Hayden,Stephen R, ED - Barkin,Roger M, ED - Schaider,Jeffrey J, BT - 5-Minute Emergency Consult UR - https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307226/all/Hemorrhoid PB - Lippincott Williams & Wilkins ET - 5 DB - Emergency Central DP - Unbound Medicine ER -