Boots WebMD Partners in Health
Return To Boots

Digestive health centre

Piles (haemorrhoids) – basics, symptoms and treatment

What are haemorrhoids?

Haemorrhoids, commonly known as piles, are swollen blood vessels in or around the anus and rectum. The haemorrhoidal veins are located in the lowest part of the rectum and the anus. Sometimes they swell so that the vein walls become stretched, thin, and irritated by passing bowel movements. Haemorrhoids are classified into two general categories - internal and external.


Internal haemorrhoids lie far enough inside the rectum that you can't see or feel them. They don't usually hurt because there are few pain-sensing nerves in the rectum. Bleeding may be the only sign that they are there. Sometimes internal haemorrhoids prolapse, or enlarge and protrude outside the anal sphincter. If so, you may be able to see or feel them as moist, pink pads of skin that are pinker than the surrounding area. Prolapsed haemorrhoids may hurt because they become irritated by rubbing from clothing and sitting. They usually recede into the rectum on their own; if they don't, they can be gently pushed back into place.

External haemorrhoids lie within the anus and are often uncomfortable. If an external haemorrhoid prolapses to the outside (usually in the course of passing a stool), you can see and feel it. Blood clots sometimes form within prolapsed external haemorrhoids, causing an extremely painful condition called a thrombosis. If an external haemorrhoid becomes thrombosed, it can look rather frightening, turning purple or blue, and could possibly bleed. Despite their appearance, thrombosed haemorrhoids are usually not serious and will resolve themselves in about a week. If the pain is unbearable, the thrombosed haemorrhoid can be removed with surgery, which stops the pain.

Anal bleeding and pain of any sort is alarming and should be evaluated - it can indicate a life-threatening condition, such as bowel cancer. Haemorrhoids are the main cause of anal bleeding and are rarely dangerous, but a definite diagnosis from your doctor is essential.

What causes haemorrhoids?

Anyone at any age can be affected by piles. They are very common, with about 50% of people experiencing them at some time in their life. However, they are usually more common in elderly people and during pregnancy. Researchers are not certain what causes haemorrhoids. "Weak" veins - leading to haemorrhoids and other varicose veins - may be inherited.

It's likely that extreme abdominal pressure causes the veins to swell and become susceptible to irritation. The pressure can be caused by obesity, pregnancy, standing or sitting for long periods, straining on the toilet, coughing, sneezing, vomiting, and holding your breath while straining to do physical labour.

Diet has a pivotal role in causing - and preventing - haemorrhoids. People who consistently eat a high-fibre diet are less likely to get haemorrhoids, but those who prefer a diet high in processed foods are at greater risk of haemorrhoids. A low-fibre diet or inadequate fluid intake can cause constipation, which can contribute to haemorrhoids in two ways: it promotes straining on the toilet and it also aggravates the haemorrhoids by producing hard stools that further irritate the swollen veins.

WebMD Medical Reference

Popular slideshows & tools on BootsWebMD

How to help headache pain
rash on skin
Top eczema triggers to avoid
Causes of fatigue & how to fight it
Tips to support digestive health
woman looking at pregnancy test
Is your body ready for pregnancy?
woman sleeping
Sleep better tonight
Treating your child's cold or fever
fifth disease
Illnesses every parent should know
spoonfull of sugar
Surprising things that harm your liver
woman holding stomach
Understand this common condition
What your nails say about your health