What causes hemorrhoids?

Hemorrhoids are associated with constipation and straining at bowel movements. Pregnancy is also associated with hemorrhoids. These conditions lead to increased pressure within the hemorrhoidal veins that causes them to swell. Hemorrhoids are usually caused by increased pressure on the veins in the pelvic and rectal area. As pressure increases, blood pools in veins and causes them to swell. Eventually, the swollen veins stretch the surrounding tissue, and hemorrhoids develop.

Experts are divided on exactly what causes hemorrhoids, but probably several mechanisms are at work. Traditionally, hemorrhoids are associated with chronic constipation, straining during bowel movements, and prolonged sitting on the toilet — all of which interfere with blood flow to and from the area, causing it to pool and enlarge the vessels. This also explains why hemorrhoids are common during pregnancy, when the enlarging uterus presses on the veins. 

Hemorrhoids and what to do about them 

• Sitz. A sitz bath is a warm water bath for the buttocks and hips (the name comes from the German “sitzen,” meaning “to sit”). It can relieve itching, irritation, and spasms of the sphincter muscle. Pharmacies sell small plastic tubs that fit over a toilet seat, or you can sit in a regular bathtub with a few inches of warm water. Most experts recommend a 20-minute sitz bath after each bowel movement and two or three times a day in addition. Take care to gently pat the anal area dry afterward; do not rub or wipe hard. You can also use a hair dryer to dry the area.   
• Get more fiber. Add more fiber to your diet from food, a fiber supplement (such as Metamucil, Citrucel, or Fiber Con), or both. Along with adequate fluid, fiber softens stools and makes them easier to pass, reducing pressure on hemorrhoids. High-fiber foods include broccoli, beans, wheat and oat bran, whole-grain foods, and fresh fruit. Fiber supplements help decrease hemorrhoidal bleeding, inflammation, and enlargement. They may also reduce irritation from small bits of stool that are trapped around the blood vessels. Some women find that boosting fiber causes bloating or gas. Start slowly, and gradually increase your intake to 25–30 grams of fiber per day. Also, increase your fluid intake. 
• Exercise. Moderate aerobic exercise, such as brisk walking 20–30 minutes a day, can help stimulate bowel function. 
• Seek topical relief. Over-the-counter hemorrhoid creams containing a local anesthetic can temporarily soothe pain. Creams and suppositories containing hydrocortisone are also effective, but don’t use them for more than a week at a time, because they can cause the skin to atrophy. Witch hazel wipes (Tucks) are soothing and have no harmfu l effects. A small ice pack placed against the anal area for a few minutes can also help reduce pain and swelling. Finally, sitting on a cushion rather than a hard surface helps reduce the swelling of existing hemorrhoids and prevents the formation of new ones. 
• Take time. When you feel the urge to defecate, go to the bathroom immediately; don’t wait until a more convenient time. Stool can back up, leading to increased pressure and straining. Also, schedule a set time each day, such as after a meal, to sit on the toilet for a few minutes. This can help you establish a regular bowel habit.   
• Treat the clot. When an external hemorrhoid forms a blood clot, the pain can be excruciating. If the clot has been present for longer than two days, apply home treatments for the symptoms while waiting for it to go away on its own. If the clot is more recent, the hemorrhoid can be surgically removed or the clot withdrawn from the vein in a minor office procedure performed by a surgeon.