Definition and epidemiology
Hemorrhoids are not abnormal vascular growths but rather normal anal cushions (vascular, connective tissue, and smooth muscle) that become symptomatic when they enlarge, prolapse, or thrombose. They are classified by their location relative to the dentate line:
- Internal hemorrhoids: arise above the dentate line, covered by columnar/transitional mucosa, visceral innervation (painless)
- External hemorrhoids: arise below the dentate line, covered by squamous epithelium, somatic innervation (painful if thrombosed)
Hemorrhoidal disease is one of the most common anorectal conditions, with estimated prevalence in the general population around 4-5%, though many cases are subclinical or unreported. Prevalence rises with age, peaking in the 45-65 year range, and is roughly equal between men and women, though women more often present during pregnancy and the postpartum period.
- Internal hemorrhoids are painless (above dentate line, visceral innervation); external hemorrhoids are painful when thrombosed (below dentate line, somatic innervation)
- Most common cause of painless bright red rectal bleeding in adults
- Sliding anal cushion theory is the currently favored pathophysiologic mechanism
- Goligher grading (I-IV) determines management for internal hemorrhoids
- Rubber band ligation is first-line procedural therapy for grade I-III internal hemorrhoids
- Excisional hemorrhoidectomy is most effective but most painful; stapled hemorrhoidopexy has less pain but higher recurrence
- Always exclude colorectal cancer and IBD before attributing bleeding to hemorrhoids, especially age over 45-50 or alarm features
- Thrombosed external hemorrhoid presenting within 48-72 hours: excision gives fastest symptom relief
Etiology and risk factors
The precise cause is multifactorial, centered on increased venous pressure and weakening of the supporting connective tissue (Treitz's muscle) that normally anchors the anal cushions.
- Chronic constipation or straining during defecation
- Prolonged sitting on the toilet or low-fiber diet
- Pregnancy and childbirth (increased pelvic venous pressure)
- Chronic diarrhea
- Obesity and sedentary lifestyle
- Aging (connective tissue laxity)
- Elevated intra-abdominal pressure (ascites, pelvic mass, heavy lifting)
- Portal hypertension does not directly cause hemorrhoids (a common misconception); it causes separate anorectal varices
Pathophysiology
Two complementary theories explain hemorrhoid formation:
- Vascular theory: abnormal dilation of the internal hemorrhoidal venous plexus and arteriovenous connections leads to venous engorgement.
- Sliding anal cushion theory (currently favored): repetitive straining and increased intra-abdominal pressure cause gradual deterioration of the connective tissue (Treitz's muscle) that suspends the anal cushions, allowing them to slide downward, engorge, and prolapse.
Thrombosis of an external hemorrhoid occurs when stasis within the venous plexus leads to clot formation, producing a tense, painful, bluish perianal nodule. Chronic prolapse of internal hemorrhoids can cause mucosal congestion, bleeding, and eventually mucus discharge or incontinence of minor degree.
Clinical features
Internal hemorrhoids
- Painless bright red rectal bleeding, typically coating the stool or on toilet paper (not mixed within stool)
- Prolapse with defecation, which may reduce spontaneously or require manual reduction
- Mucus discharge, perianal moisture, pruritus
- Sensation of incomplete evacuation
External hemorrhoids
- Painless unless thrombosed
- Thrombosed external hemorrhoid: sudden onset of severe perianal pain, a tender palpable bluish lump, worst in the first 24-72 hours
Grading of internal hemorrhoids (Goligher classification)
| Grade | Description |
|---|---|
| I | Bleed, no prolapse |
| II | Prolapse with straining, reduce spontaneously |
| III | Prolapse, require manual reduction |
| IV | Permanently prolapsed, irreducible |
Diagnosis
Diagnosis is primarily clinical, based on history and physical exam.
- Inspection: perianal exam at rest and during straining (Valsalva) identifies prolapse and external hemorrhoids
- Digital rectal exam (DRE): assesses sphincter tone, masses, and tenderness; internal hemorrhoids are usually not palpable unless thrombosed or large
- Anoscopy: direct visualization of internal hemorrhoids, confirms grade
- Flexible sigmoidoscopy or colonoscopy: indicated in patients over 45-50 years, those with alarm features (weight loss, change in bowel habits, iron deficiency anemia, family history of colorectal cancer, blood mixed with stool), or when diagnosis is uncertain, to exclude colorectal neoplasm or inflammatory bowel disease
Key teaching point: never attribute rectal bleeding to hemorrhoids without excluding more serious pathology, especially in patients over 45-50 or with any alarm feature. In average-risk patients over 45-50 presenting with rectal bleeding, colonoscopy is generally warranted even if anoscopy identifies hemorrhoids, since the two findings can coexist.
Differential diagnosis
- Anal fissure: painful defecation with sharp, tearing pain and small amount of bright red blood; posterior midline tear visible on exam
- Colorectal cancer: change in bowel habits, weight loss, iron deficiency anemia, blood mixed with stool
- Anorectal abscess or fistula: fever, perianal swelling, purulent discharge
- Rectal prolapse: full-thickness circumferential protrusion with concentric mucosal folds, distinct from the radial folds of prolapsed hemorrhoids
- Condyloma acuminata (anal warts): HPV-related, cauliflower-like lesions
- Inflammatory bowel disease: diarrhea, systemic symptoms, perianal fistulas (Crohn disease)
- Anorectal varices: seen in portal hypertension, distinct entity from hemorrhoids
Management
Management is graded, moving from conservative to surgical based on severity and failure of prior therapy.
Conservative (first-line, all grades)
- Increased dietary fiber (20-35 g/day) and fluid intake
- Avoidance of straining and prolonged toilet sitting
- Sitz baths (warm water soaks)
- Topical agents: corticosteroid or anesthetic creams for symptomatic relief (short-term use only)
Office-based procedures (Grade I-III)
- Rubber band ligation: first-line procedural therapy for grade I-III internal hemorrhoids, most effective non-surgical option
- Sclerotherapy (injection) and infrared coagulation: alternatives, generally lower efficacy than banding
Surgical (Grade III-IV, failed conservative/office therapy, or combined internal-external disease)
- Excisional hemorrhoidectomy: most effective, definitive treatment, but most painful with longest recovery
- Stapled hemorrhoidopexy: less postoperative pain, but higher recurrence/prolapse risk than excisional surgery
- Doppler-guided hemorrhoidal artery ligation: less invasive alternative in select centers
Thrombosed external hemorrhoid
- If presenting within 48-72 hours and severe pain: surgical excision (not just incision) offers fastest relief
- If presenting later or pain is improving: conservative management (analgesia, sitz baths, fiber), since pain typically peaks early and resolves over 1-2 weeks
Guideline bodies (American Society of Colon and Rectal Surgeons, major European coloproctology societies) broadly agree on this stepwise approach; minor variation exists regarding thresholds for choosing stapled hemorrhoidopexy versus excisional hemorrhoidectomy.
Complications and prognosis
- Thrombosis of external hemorrhoids (acute pain)
- Strangulation: irreducible prolapsed internal hemorrhoid with compromised blood supply, a surgical emergency
- Chronic bleeding leading to iron deficiency anemia (uncommon but can occur with persistent bleeding)
- Anal stenosis or incontinence as rare complications of surgical treatment
- Infection/abscess: rare
Prognosis is generally excellent. Most patients improve with conservative and office-based measures; recurrence is common with lifestyle factors unaddressed. Surgical hemorrhoidectomy has the lowest recurrence rate but carries the most postoperative discomfort.
Grading mnemonic 'PIPS' for Goligher grades: Protrudes with straining and reduces spontaneously (II), Irreducible/permanently prolapsed (IV), Prolapses and needs manual reduction (III), Spotting/bleeding only, no prolapse (I) — remember order I-IV as bleeding only -> spontaneous reduction -> manual reduction -> permanent prolapse.
Practice questions
1. A 52-year-old man reports painless bright red blood on the toilet paper after bowel movements for the past 3 months, with occasional protrusion of tissue that reduces spontaneously after defecation. He has no weight loss, no change in bowel habits, and no family history of colorectal cancer. Anoscopy confirms enlarged internal hemorrhoids. What is the most appropriate next step in management?
2. A 34-year-old woman presents with 12 hours of severe perianal pain. On exam, there is a tender, firm, bluish 1.5 cm nodule at the anal verge. There is no fever or purulent drainage. What is the most appropriate management?
3. A 68-year-old woman has a permanently prolapsed, irreducible internal hemorrhoid that has failed multiple rubber band ligation attempts. She has no bleeding disorder and is otherwise a good surgical candidate. Which treatment offers the lowest recurrence rate?
Frequently asked questions
What causes hemorrhoids?
Hemorrhoids result from increased pressure on the anal cushions, usually from chronic straining, constipation, pregnancy, or prolonged sitting, which weakens the connective tissue anchoring these normal vascular structures and allows them to engorge and slide downward. Low-fiber diet, obesity, and aging are additional contributing factors. Portal hypertension does not directly cause hemorrhoids.
What are the first symptoms of hemorrhoids?
The earliest and most common symptom is painless bright red bleeding noticed on toilet paper or coating the stool after a bowel movement. Other early symptoms include perianal itching, mild discomfort, or a sensation of a lump or incomplete evacuation. External hemorrhoids typically remain painless unless they become thrombosed, which causes sudden sharp pain.
How are hemorrhoids diagnosed?
Diagnosis is made clinically through visual inspection of the perianal area, digital rectal examination, and anoscopy to directly visualize and grade internal hemorrhoids. In patients over 45-50 years or with alarm features such as weight loss or anemia, colonoscopy or flexible sigmoidoscopy is performed to rule out colorectal cancer or inflammatory bowel disease before attributing symptoms to hemorrhoids.
Are hemorrhoids curable?
Yes, hemorrhoids are highly treatable, though recurrence is common if underlying risk factors like constipation and straining are not addressed. Most cases resolve with dietary fiber, hydration, and topical therapy. Grades that fail conservative measures respond well to office procedures like rubber band ligation, and surgical hemorrhoidectomy offers the lowest recurrence rate for severe or refractory disease.
Hemorrhoids vs anal fissure — what is the difference?
Hemorrhoids typically cause painless bleeding with possible prolapse, while anal fissures cause sharp, tearing pain during and after defecation with only minor bleeding. On exam, fissures appear as a linear tear, usually in the posterior midline, whereas hemorrhoids appear as bulging vascular cushions. Fissures are often associated with a visible sentinel skin tag, and hemorrhoids with prolapsing tissue.
Key drugs
Related conditions and differentials
Sources and further reading
StatPearls (NCBI Bookshelf)MedlinePlusWHO ICD-10: K64
Educational content for medical students, prepared by the WhiteCoat Pro editorial team with AI assistance; every page is reviewed by a second AI model for factual errors. It is not medical advice and does not replace the product label, local guidelines or a clinician.