Hemorrhoids are dilated submucosal vascular cushions within the anal canal that can be asymptomatic or manifest as painless perianal masses, pruritus, or intermittent scant hematochezia (bright red blood per rectum, typically at the end of defecation). Excessive straining during defecation or intraabdominal pressure (e.g., due to constipation, pregnancy, or prolonged periods sitting) increase the likelihood of developing hemorrhoids. Based on their anatomical location, hemorrhoids are internal (above the dentate line), external (below the dentate line), or mixed. Internal hemorrhoids are classified into four grades according to the extent of prolapse. The diagnosis is primarily clinical, based on a thorough history and examination that includes a digital rectal examination and anoscopy. Further investigation with proctoscopy, sigmoidoscopy, or colonoscopy may be required to rule out differential diagnoses of hemorrhoids, including colorectal cancer. All patients with symptomatic hemorrhoids should be counseled on lifestyle modifications (e.g., increased fiber and fluid intake, regular physical activity) to reduce straining during defecation. Medical management also includes stool softeners and short-term use of topical medications (e.g., anesthetics, corticosteroids, or vasoconstrictors) for symptomatic relief. Hemorrhoids refractory to medical management and larger (grades III and IV) internal hemorrhoids typically require procedures such as rubber band ligation, sclerotherapy, and infrared coagulation, or surgery. Thrombosed external hemorrhoids manifest with acute pain and a tender bluish-purple perianal nodule. Surgical excision of the thrombosed hemorrhoid may be beneficial in patients who present within 3–4 days of symptom onset. Those who present later should be managed conservatively.
Anatomy of the anal canal
- Areas of thickened anal mucosa that consist of arteriovenous blood vessels (corpus cavernosum recti), smooth muscle (e.g., Treitz muscle), and fibroelastic tissue (e.g., collagen, elastic fibers)
- Located at 11, 7 and 3 o'clock in the lithotomy position (right anterior, right posterior, and left lateral position)
- Play an important role in maintaining continence by enabling tight closure of the rectum
- Defecation causes contraction of supportive structures (e.g., Treitz muscle) → compression of anal cushions → increased diameter of the anal canal for adequate passage of stool
- Anal columns: longitudinal folds of mucous membrane that are fused at their inferior ends by transverse folds (anal valves)
- Anal sinuses: small, mucus-secreting pouches between the anal columns above the anal valves
- Dentate line
- External anal sphincter
- Internal anal sphincter
|Characteristics of the anal canal above and below the dentate line |
|Above the dentate line||Below the dentate line|
|Embryological origin|| |
Internal vs. external hemorrhoids
Hemorrhoids are classified as internal , external , or mixed .
- Prolapse of internal hemorrhoids, with possible incarceration and strangulation, may cause pain by triggering an anal sphincter complex spasm. → possible ischemia and necrosis of internal hemorrhoids → worsening anal sphincter complex spasm → potential external hemorrhoid thrombosis → cutaneous pain
- Develop above the dentate line, which is not innervated by cutaneous nerves; distension does not cause pain.
- Bleeding and/or prolapsed internal hemorrhoids irritate sensitive perianal skin → perianal itching
- External hemorrhoids
Hemorrhoids are not varicose veins (dilated, tortuous veins). Anorectal varices occur, e.g., as a result of portal hypertension. The terms anorectal varices and hemorrhoids are often used interchangeably, but this is incorrect.
- Often painless, bright red bleeding at the end of defecation
- Perianal mass in the event of prolapse
- Anal discharge (containing mucus or fecal debris)
- Ulceration (in IV)
- External hemorrhoids
|Grading of internal hemorrhoids |
|I||Hemorrhoids bleed but do not prolapse.|
|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|
- All patients with suspected hemorrhoids: Perform a perianal examination, digital rectal examination, and anoscopy.
- Inconclusive initial evaluation: Refer for proctoscopy or flexible sigmoidoscopy to evaluate the rectum and distal colon.
- Concern for malignancy (age ≥ 50 years , , ): Colonoscopy (alternatively, CT colonography) is required to evaluate the entire colon. 
Hemorrhoids are a clinical diagnosis.
Physical examination 
- Evaluate in the prone jackknife position, lateral decubitus position, or lithotomy position. 
- Inspect the perianal area for external hemorrhoids and nonreduced internal hemorrhoids.
- Perform a digital rectal examination to evaluate for masses or tenderness.
- Ask the patient to perform the Valsalva maneuver in order to assess for any prolapse of grade II or III hemorrhoids or rectal mucosa.
- Rule out other potential sources of bright red blood per rectum or perianal masses (see “Differential diagnoses of hemorrhoids”).
- Insertion of an anoscope to directly visualize the anus and distal rectum 
- Perform in all patients with suspected hemorrhoids. 
- May show hemorrhoids or differential diagnoses, e.g., anal carcinoma or fissure
Further studies 
- Anal skin tags: benign, painless folds of skin at the anal verge that are residues of previous episodes of inflammation or thrombosed hemorrhoids 
- Hypertrophied anal papillae
- Anal and colorectal carcinoma
- Anal fissures (cause painful bright red bleeding per rectum)
- Anorectal varices
- Condyloma acuminata
- Inflammatory bowel disease (often associated with anal fistulas and abscesses)
- Rectal prolapse
- Perianal dermatitis
Always consider the possibility of concurrent colorectal carcinoma.
The differential diagnoses listed here are not exhaustive.
- All patients with symptomatic hemorrhoids
- Lifestyle modifications to reduce straining during defecation
- Sitz baths and topical medications for short-term symptomatic relief
- Internal hemorrhoids
- External hemorrhoids
Hemorrhoids should only be treated in symptomatic patients. 
Medical management 
- Indications: all patients with hemorrhoids
Interventions to reduce anorectal pressure and straining
Lifestyle modifications 
- High fiber diet (20–30 g/day)
- Increased fluid intake
- Avoidance of fatty foods
- Regular physical activity
- Avoidance of excessive straining 
- Limiting the amount of time spent on the toilet
- Short-term (up to 1 week) use of stool softeners (e.g., docusate) or laxatives (e.g., polyethylene glycol 3350) as needed 
- Lifestyle modifications 
- Interventions to alleviate symptoms (e.g., pain, pruritus)
Long-term use of topical medications for hemorrhoids can lead to sensitization and localized reactions and should be avoided. 
Office-based procedures 
- Indications: grade I–III internal hemorrhoids with symptoms refractory to medical management 
- Rubber band ligation: most common 
- : low risk of bleeding; consider for patients on anticoagulants 
- Infrared coagulation: application of infrared light waves to the base of the hemorrhoid under vision to induce necrosis and scar formation; typically performed for grade I–II internal hemorrhoids 
- Potential complications: uncommon; can include bleeding, pain, or infection (including perianal sepsis) 
- Indications 
- Submucosal hemorrhoidectomy: surgical removal of hemorrhoids 
- Stapled hemorrhoidopexy (Longo procedure) 
- Doppler-guided hemorrhoidal arterial ligation: identification and ligation of the arteries supplying hemorrhoids
- Potential complications: pain, bleeding, acute urinary retention, and rarely, anal stricture/stenosis
Pain is common after surgical treatment of hemorrhoids. Consider multimodal analgesia including local anesthesia and use of topical medications (e.g., diltiazem or nitroglycerin ointment) to reduce the need for opioid analgesics. 
Clinical features 
- Acute onset of severe perianal pain
- Painful perianal mass that may ulcerate and bleed
- Painful defecation
- Typically a clinical diagnosis
- Perianal examination: a palpable, tender, dark red to purplish nodule at the anal verge or just within the anal canal
Conservative management 
- Patients who present after > 3–4 days of symptom onset
- An alternative to surgery in patients with mild or moderate symptoms who present early
distal to the dentate (pectinate) line are located and are drained by the inferior hemorrhoidal (rectal) plexus. External hemorrhoid thrombosis occurs if a clot forms in the inferior hemorrhoidal plexus.