As the anal cushion of an internal haemorrhoid enlarges, it bulges into the anal canal, loses its normal anchoring, and protrude from the anus as a prolapsing internal haemorrhoid.
The haemorrhoid is exposed to the trauma of passing hard stool, which causes bleeding and sometimes pain. The rectal lining that has been pulled down can secrete mucus.
The presence of stool and constant moisture can lead to anal itchiness (pruritus ani), though itchiness is not a common symptom of haemorrhoids.
First-degree hemorrhoids:
bleed but do not prolapse (do not protrude from the anus).
Second-degree hemorrhoids:
prolapse and retract on their own, with or without bleeding.
Third-degree hemorrhoids:
prolapse but must be pushed back in by a finger.
Fourth-degree hemorrhoids:
prolapse and cannot be pushed back in.
Key Points:
Only when haemorrhoidal cushions enlarge that haemorrhoids can cause problems and be considered abnormal or a disease. Common symptoms include
- Prolapse
- Rectal bleeding
- Pain (less often)
- Anal itchiness (sometimes)