In a normal human being at the lower part of the rectum and in the anal canal area several vessels are present which helps to control defecation and also acts as cushions at these areas. Sometimes these vessels can become swollen, engorged or inflamed resulting into a pathological condition known as piles or hemorrhoids.

The presenting symptoms of piles depend upon the location of the swollen vessels. There are two types of piles, internal (arising from the rectal wall and extending within the cavity of the rectum) and external piles or hemorrhoids (arising beneath the skin surrounding the anal opening).
The exact cause which leads to hemorrhoids or piles is not known however the most important factors which increases the chance of suffering from hemorrhoids is increase in the pressure within the abdominal cavity (intrabdominal pressure). The most common cause of raised intrabdominal pressure is constipation.

For mild to moderate degree of involvement of vessels change in diet like increased consumption of food containing high fiber, plenty of oral fluid etc, intake of NSAIDs to relieve the pain and taking adequate rest is sufficient to relieve the symptoms. There are several minor surgical procedures practiced which help to relieve the condition if the above mentioned conservative management fails.
Piles or hemorrhoids are quite common about half of the total population suffer from hemorrhoids at least once in their lifetime. The outcome of hemorrhoids or piles is quite good following treatment.

Symptoms
The presenting symptoms of hemorrhoids differ from person mainly because the two types of hemorrhoids present differently, although sometimes combination of both the symptoms may also occur.
1. External hemorrhoids: In case of this type of hemorrhoids there are few or no presenting symptoms until and unless the blood in the affected swollen vessels becomes clotted (thrombosed). Thrombosed hemorrhoids are painful; although the severity of pain usually varies from person to person. However pain usually resolves within 2 to 3 days. Another common symptom is swelling which is usually relieved within weeks. Sometimes skin tag may persist even after resolution of swelling and pain and may lead to irritation, itching in the skin surrounding the anal opening.
2. Internal hemorrhoids: In these types of hemorrhoids the most common presenting symptoms include painless bleeding from rectum during or immediately after passing stool. In most of the cases the blood usually covers the stool, on the toilet paper or present in the toilet bowl following passing of stool. One of the important characteristic of bleeding associated with piles is that the stool color is normal. Other common symptoms include passage of mucous, itching sensation in the anal area, inability to control bowel movement etc. Pain occurs in internal hemorrhoids only when there is blood clotting (thrombosed hemorrhoids) or necrosis.

Rarely bleeding associated with piles may lead to severe degree of anemia. Strangulated hernia is another complication associated with piles. When the blood supply to the internal hemorrhoids is somehow blocked strangulation of the hemorrhoids occur resulting into severe degree of pain and loss of tissue (known as gangrene).