Causes of Hemorrhoids

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Hemorrhoids are a common affliction. Estimates are that up to half of the population are affected by the pain and discomfort of hemorrhoids at some point in their life. Not surprisingly, most hemorrhoid sufferers are too embarrassed to talk about their problem and either suffer in silence or use home remedies to treat them. What are the causes of hemorrhoids?

Understanding the Possible Hemorrhoid Causes

Hemorrhoids are dilated veins located in the anus and rectum. There are a variety of theories as to what causes hemorrhoids, but none of them are proven. The best accepted one is that hemorrhoids are caused by increased pressure within the veins that line the anus and rectum. This increased pressure causes them to dilate and leads to the irritation, burning and itching that so many hemorrhoid sufferers experience.

A variety of factors can increase pressure in the anal and rectal veins including prolonged standing or sitting, lifting heavy objects and medical conditions such as heart failure and liver disease. Some experts believe this isn’t the actual cause of hemorrhoids, but instead these activities and conditions make the symptoms of hemorrhoids worse.

Not surprisingly, toilet habits contribute to hemorrhoids. Straining to have a bowel movement has been proposed as the primary cause of hemorrhoids, but according to information published in, spending long periods of time sitting on the toilet may be a bigger part of the problem. Being in this position for too long relaxes the connective tissue that supports the veins. Age plays a role too since connective tissue weakens with age, which gives the veins less support.

Constipation, Pregnancy and Diet

Constipation makes it more difficult to have a bowel movement, which leads to straining, but loose bowel movements can be a problem too. According to a study published in the journal Primary Care, diarrhea is more closely linked with hemorrhoids than constipation. It’s likely that neither extreme is ideal when it comes to the discomfort and irritation of hemorrhoids.

Pregnancy is another time when hemorrhoids are more common. The increasing pressure of the growing baby puts additional pressure on veins in the pelvis. This causes veins in the lower half of the body, including the anus and rectum, to dilate. Many pregnant women have problems with constipation and may strain more to have a bowel movement, which makes the problem worse.

Not surprisingly, diet plays a role in hemorrhoids. Areas of the world that mainly eat a high-fiber, plant-based diet have a lower risk of hemorrhoids than countries that eat processed foods that are low in fiber. A high-fiber diet increases stool bulk and reduces constipation and straining.

The Bottom Line?

The exact causes of hemorrhoids aren’t completely understood, but conditions and behaviors that put additional pressure on the veins in the anus and rectum increase the risk of getting them – especially pregnancy and straining with bowel movements.


Hemorrhoids. Primary Care. 1999; 26(1): 35-51.

Diseases of the Colon & Rectum. Volume 25, Number 5, 454-456. “Hemorrhoids: Self-Care vs. Physician Care”