• Clinical science



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

Characteristics of the anal canal above and below the dentate line
Above the dentate line Below the dentate line
Embryological origin

Arterial supply

Venous drainage
Lymphatic drainage
Clinical relevance


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.


Clinical features



Hemorrhoids are a clinical diagnosis!


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

Other procedures

  • Flexible sigmoidoscopy, colonoscopy, or barium enema: to exclude suspected malignancy (especially in patients over the age of 40)


Differential diagnoses

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

  • Indications: grade I–II internal hemorrhoids and external hemorrhoids
  • Interventions
    • Lifestyle modifications: weight loss, exercise, high fiber diet, avoid fatty and spicy foods, increase water intake
    • Alter stool habits (e.g., avoid excessive straining or > 5 min periods on the toilet)
    • Sitz baths
    • Stool softeners (e.g., docusate)
    • Topical or suppository analgesia (e.g., lidocaine)
    • Topical anti‑inflammatory (e.g., hydrocortisone, especially with pruritus, but no longer than 1 week)
    • Topical antispasmodic agents (e.g., nitroglycerin)

Outpatient treatment

  • Indications: all internal hemorrhoids with symptoms persisting despite conservative treatment and grade III internal hemorrhoids
  • Interventions
    • Rubber band ligation (RBL)
    • Sclerotherapy
    • Infrared coagulation

Surgical treatment (stages III–IV)



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.