hemorrhoids

Hemorrhoids are normal vascular structures in the anal canal that become pathologically engorged and prolapsed due to increased intra-abdominal/intrarectal pressure. Risk factors include chronic constipation, straining during defecation, pregnancy, obesity, prolonged sitting, low-fiber diet, and portal hypertension (though hemorrhoids are not true varices and are not significantly worsened by portal hypertension despite common misconception—rectal varices are a distinct entity seen in portal hypertension).

Internal hemorrhoids arise above the dentate line, are covered by columnar/transitional epithelium, and are innervated by visceral afferents—thus typically painless. They present with bright red blood per rectum (often coating stool or on toilet paper), and can prolapse. They are graded I-IV based on degree of prolapse: Grade I (no prolapse), II (prolapse with straining, reduces spontaneously), III (prolapse requiring manual reduction), IV (irreducible prolapse).

External hemorrhoids arise below the dentate line, are covered by squamous epithelium, and are innervated by somatic nerves (inferior rectal nerve)—thus painful, especially if thrombosed. Thrombosed external hemorrhoids present as a tender, bluish perianal nodule.

Complications include thrombosis, ulceration, and rarely strangulation of prolapsed internal hemorrhoids.

Management: conservative measures (increased fiber, fluids, sitz baths, topical agents) for mild cases; rubber band ligation or sclerotherapy for higher-grade internal hemorrhoids; surgical hemorrhoidectomy for refractory or thrombosed cases.

High-yield boards point: distinguish hemorrhoids from anal fissures (painful, linear tear, often posterior midline, associated with constipation) and from colorectal cancer (which can also cause rectal bleeding—important to rule out in patients >50 or with alarm symptoms like weight loss, anemia, change in bowel habits).