Classification of haemorrhoids

Haemorrhoids may be either:

• internal:
  • with an origin above the dentate line
  • are generally painless unless they become strangulated
    
    
• external:
  • with an origin below the dentate line
  • are generally painful as they are covered by sensate skin

Haemorrhoids may be of four grades:

• grade I:
  • do not prolapse out of the anal canal
    
    
• grade II:
  • prolapse on defecation but reduce spontaneously on cessation of straining
    
    
• grade III:
  • require manual reduction to reduce fully
    
    
• grade IV:
  • cannot be reduced manually