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Last updated: September 6, 2021

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Hemorrhoids, also called piles, arise from a cushion of dilated arteriovenous blood vessels and connective tissue in the anal canal that may abnormally enlarge or protrude. Hemorrhoids are divided into three categories: internal (above the dentate line), external (below the dentate line), or mixed (above and below the dentate line). Hemorrhoids are caused by increased straining or intra-abdominal pressure (e.g., due to constipation, pregnancy, or extended periods of sitting). Patients may present with prolapse, rectal bleeding, pain, and pruritus. The diagnosis of hemorrhoids involves careful inspection of the anal area during clinical examination, especially as the patient increases intra‑abdominal pressure by straining. Anoscopy and proctoscopy may be necessary to confirm the diagnosis. Internal hemorrhoids are classified into four grades, depending upon the extent of prolapse: Conservative management is recommended in grades I and II (anal hygiene, anti‑inflammatory ointments), while surgical intervention is indicated in grades III and IV (e.g., Milligan‑Morgan hemorrhoidectomy).

Internal hemorrhoid stages
Grade Palpation findings
I Hemorrhoids do not prolapse (only project into the anal canal); above the dentate (pectinate) line; reversible; often bleed
II Prolapse when straining, but spontaneously reduce at rest
III Prolapse when straining; only reducible manually
IV Irreducible prolapse; may be strangulated and thrombosed with possible ulceration

There is no widely used classification system for external hemorrhoids.

Anatomy of the anal canal

Internal vs. external hemorrhoids

Hemorrhoids are classified as internal , external , or mixed .

Hemorrhoids are not varicose veins (widening of the veins)! However, anorectal varices do exist and may occur, e.g., as a result of portal hypertension. The terms anorectal varices and hemorrhoids are often used interchangeably, but this is incorrect.


Hemorrhoids are a clinical diagnosis.


  • For assessing the anus and distal rectum
  • Useful when hemorrhoids are suspected but rectal examination is inconclusive [5]
  • In addition, proctoscopy may be used to support anoscopy findings.

Other procedures


Always consider the possibility of concurrent colorectal carcinoma!

The differential diagnoses listed here are not exhaustive.

Hemorrhoids should only be treated in a symptomatic patient!

Conservative treatment

Outpatient treatment

Surgical treatment (stages III–IV) [6]

  • Indications: grade IV internal hemorrhoids and no improvement of condition after clinical interventions
  • Interventions
    • Arterial ligation of hemorrhoids (HAL)
    • Submucosal hemorrhoidectomy
      • Ferguson approach (closed approach )
      • Milligan‑Morgan approach (open approach )
    • Stapled hemorrhoidopexy (e.g., using the Longo procedure): only effective for internal hemorrhoids


Hemorrhoid disease

  • Internal: prolapse of internal hemorrhoid → accumulation of mucus and fecal debris in external anal tissue → local irritation and inflammation
  • External: may become acutely thrombosed (e.g., with excessive straining) → necrosis of overlying skin and bleeding


We list the most important complications. The selection is not exhaustive.

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  2. Robertson M, Thompson AI, Hayes PC. The Management of Bleeding from Anorectal Varices. Current Hepatology Reports. 2017; 16 (4): p.406-415. doi: 10.1007/s11901-017-0382-6 . | Open in Read by QxMD
  3. Standring S. Gray's Anatomy: The Anatomical Basis of Clinical Practice. Elsevier Health Sciences ; 2016
  4. Garden OJ, Bradbury AW, Forsythe JLR, Parks RW. Principles and Practice of Surgery. Elsevier Health Sciences ; 2012
  5. Mounsey AL, Halladay J, Sadiq TS . Hemorrhoids. Am Fam Physician. 2011; 84 (2): p.204-210.
  6. Beck DE, Rombeau JL, Stamos MJ, Nasseri Y. The ASCRS Manual of Colon and Rectal Surgery. Springer Science+Business Media ; 2009