78 Internal Haemorrhoid

Internal haemorrhoid

A hemorrhoid classification system is useful to decide treatments, and therapeutic outcomes among them.

Hemorrhoids are generally classified on the basis of their location and degree of prolapse.

  • Internal hemorrhoids originate from the inferior hemorrhoidal venous plexus above the dentate line and are covered by mucosa
  • External hemorrhoids are dilated venules of this plexus located below the dentate line and are covered with squamous epithelium.
  • Mixed (interno-external) hemorrhoids arise both above and below the dentate line.


Internal hemorrhoids are further graded with Goligher’s classification:

  1. First-degree hemorrhoids (grade I): The anal cushions bleed but do not prolapse
  2. Second-degree hemorrhoids (grade II): The anal cushions prolapse through the anus on straining but reduce spontaneously;
  3. Third-degree hemorrhoids (grade III): The anal cushions prolapse through the anus on straining or exertion and require manual replacement into the anal canal
  4. Fourth-degree hemorrhoids (grade IV): The prolapse stays out at all times and is irreducible.

*Acutely thrombosed, incarcerated internal hemorrhoids and incarcerated, thrombosed hemorrhoids involving circumferential rectal mucosal prolapse are also fourth-degree hemorrhoids


  1. Lohsiriwat V. Hemorrhoids: from basic pathophysiology to clinical management. World J Gastroenterol. 2012 May 7;18(17):2009-17. doi: 10.3748/wjg.v18.i17.2009. PMID: 22563187; PMCID: PMC3342598.