Hemorrhoids, or piles, are enlarged blood vessels within the anal canal. They may be internal, located inside the anal canal, or external, located around the anal opening.
Common contributing factors include hereditary and anatomical factors, constipation and straining during bowel movements, low-fibre diet, diarrhoea and other bowel disorders, pregnancy, difficulty passing urine, and certain rectal or portal circulation conditions.
Internal hemorrhoids are classified according to the degree of prolapse. First-degree hemorrhoids remain inside the anal canal, second-degree hemorrhoids prolapse during bowel movements but return on their own, third-degree hemorrhoids require manual replacement, and fourth-degree hemorrhoids remain permanently prolapsed.
Persistent or significant rectal bleeding should be evaluated by a doctor, as it may have causes other than hemorrhoids.