Piles (Haemorrhoids)

Updated 16 March 2016

What are piles (haemorrhoids)?

Haemorrhoids (piles) are enlarged veins around the anal canal.


Suffering from haemorrhoids (also known as piles) are very common and have been afflicting humans for centuries. They develop when the veins in the anal canal become abnormally swollen and inflamed. Haemorrhoids result from increased pressure in the veins of the anus, causing the veins to bulge and expand, making them painful - particularly when sitting.

The most common cause of haemorrhoids is straining during bowel movements brought on by constipation, sitting for long periods of time, and anal infection. Other contributing factors include pregnancy, ageing, chronic constipation or diarrhoea, natural birth, and anal intercourse. In some cases, they can also be caused by other diseases, such as liver cirrhosis.

Haemorrhoids can develop inside the anal canal or near the opening of the anus – these types are classified as internal or external.

External haemorrhoids develop below the dentate line (a line that separates the two types of anal skin), and are generally painless. They rarely need medical treatment, unless a vein bursts, blood pools under the skin and a painful lump develops (this is called a clotted or thrombosed haemorrhoid).

Internal haemorrhoids develop above the dentate line. They can range in size from a slight swelling under the wall of the canal to large, sagging veins that protrude from the anus at all times. For treatment purposes, internal haemorrhoids are graded according to their size:

  • Grade I: The vein bulges and may bleed during bowel movements.
  • Grade II: The vein comes out of the anus during bowel movements, but goes back by itself.
  • Grade III: The vein comes out during bowel movements, but doesn't go back by itself. It has to be replaced by hand.
  • Grade IV: The vein protrudes from the anus at all times and cannot be replaced.

Classification of haemorrhoids

It is possible for a person to have both internal and external haemorrhoids at the same time.


Haemorrhoids are common in both men and women. About half of the population has haemorrhoids by age 50. Haemorrhoids are also common among pregnant women. The pressure of the foetus on the abdomen, as well as hormonal changes, cause the haemorrhoidal vessels to enlarge. These vessels are also placed under severe pressure during childbirth. For most women, however, haemorrhoids caused by pregnancy are a temporary problem.

When to see a doctor

A visit to a doctor is indicated when:

  • Rectal bleeding occurs for no apparent reason and is not associated with trying to pass stools.
  • Rectal bleeding continues for more than one week.
  • Stool becomes more narrow than usual.
  • A lump near the anus gets bigger or becomes more painful.
  • Pain and/or swelling due to haemorrhoids are severe.
  • Moderate pain lasts longer than one week after home treatment.
  • Any unusual material seeps from the anus.
  • Tissue from inside the body sticks out of the anus and does not return to normal after three to seven days of home treatment.
  • Rectal bleeding becomes heavy and/or changes in colour from bright red to dark red or if stools change in colour.

Reviewed by Prof Don du Toit (M.B.Ch.B) (D.Phil.) (Ph.D) (FCS) (FRCS).


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