Haemorrhoids are swollen veins in the lower part of the rectum and anus that can cause discomfort, itching, and bleeding. Although they rarely lead to serious complications, they affect millions of people worldwide and can significantly impact daily life and wellbeing.

How Common Are Haemorrhoids?

Haemorrhoids are an extremely widespread condition that affects people across all demographics. The exact number of people living with haemorrhoids is difficult to determine because many individuals never seek medical attention for their symptoms, either due to embarrassment or because their symptoms are mild enough to manage at home.^[1]

Research suggests that haemorrhoids are among the most common causes of problems in the anal area. Studies estimate that approximately one in twenty Americans experiences bothersome haemorrhoids at some point in their lives.^[2][3] The condition becomes increasingly prevalent with age, affecting more than half of all adults over the age of fifty.^[2][3]

Haemorrhoids affect both men and women equally and can occur across all racial and ethnic groups.^[3] When researchers conducted routine colorectal cancer screening on a group of patients, they discovered that thirty-nine percent had haemorrhoids, yet more than half of those individuals reported no symptoms at all.^[11] This finding highlights how common haemorrhoids truly are, even when people are unaware of their presence.

Between the ages of forty-five and sixty-five, haemorrhoids become particularly common as a medical complaint.^[5][11] Healthcare providers report that haemorrhoids rank as the third most common outpatient gastrointestinal diagnosis.^[4] Despite their prevalence, many patients feel too embarrassed to discuss their symptoms with doctors, which means the true number of affected individuals may be even higher than current estimates suggest.^[5]

What Causes Haemorrhoids?

Understanding what causes haemorrhoids begins with recognizing what they actually are. Everyone is born with haemorrhoids, which are normal cushions of vascular tissue containing blood vessels, smooth muscle, and connective tissue that line the anal canal.^[2][5] These structures only become problematic when they swell and enlarge, producing uncomfortable symptoms.

The primary cause of haemorrhoids is increased pressure on the veins in the rectum and anus. This pressure causes the blood vessels to swell and bulge, much like varicose veins (swollen, twisted veins) that appear in the legs.^[1][7] When too much pressure builds up in these blood vessels, they can stretch, become irritated, and cause the symptoms associated with haemorrhoids.

The exact mechanism behind why haemorrhoids develop is not completely understood by medical professionals. However, research has shown that anything putting extra pressure on the veins in the rectum and anus can lead to their development or make existing haemorrhoids worse.^[2] The walls of these blood vessels can stretch so thin that the veins bulge and become irritated, particularly during bowel movements.

Recent studies have also revealed that people with haemorrhoids tend to have a higher resting anal canal tone than average.^[12][19] This means the smooth muscle of the anal canal tends to be naturally tighter, even when a person is not straining. This increased muscle tension may contribute to the development of haemorrhoids over time.

Additionally, the connective tissues that support and hold the haemorrhoidal cushions in their proper position can weaken as people age.^[12][19] This natural weakening process causes the tissues to stretch and allows the haemorrhoids to bulge and potentially prolapse, or push through the anal opening.

Evidence also indicates that haemorrhoidal bleeding comes from arteries rather than veins, which helps explain why the blood seen with haemorrhoids is typically bright red rather than darker in color.^[5]

Risk Factors for Developing Haemorrhoids

Certain behaviors, conditions, and life circumstances can significantly increase the likelihood of developing haemorrhoids. Understanding these risk factors can help people take steps to prevent the condition or minimize symptoms.

One of the most significant risk factors is straining during bowel movements. This typically occurs when someone has constipation (infrequent or difficult passage of hard stools) or chronic diarrhea.^[2][3] When straining becomes a regular occurrence, it places repeated pressure on the veins in the anal area, eventually causing them to swell. Similarly, sitting on the toilet for extended periods increases pressure on the rectal veins and contributes to haemorrhoid formation.^[2][3]

Dietary habits play a crucial role in haemorrhoid risk. People who consume foods that are low in fiber are more susceptible to developing haemorrhoids because their diet contributes to constipation and harder stools.^[3][7] Without adequate fiber to soften stools and add bulk, bowel movements become more difficult and require more straining.

Pregnancy is another major risk factor for haemorrhoids in women. As the baby grows, the enlarged uterus puts significant pressure on the veins in the lower abdomen and pelvis.^[2][4][7] Hormonal changes during pregnancy can also contribute to the problem by affecting bowel movements and potentially causing constipation. This explains why haemorrhoids are particularly common during pregnancy and after childbirth.

Being overweight or obese increases the risk of haemorrhoids because excess body weight places additional pressure on the pelvic area and rectal veins.^[4][7] This constant pressure makes it easier for the veins to become swollen and inflamed over time.

Repeatedly lifting heavy objects can also contribute to haemorrhoid formation.^[2][4] The physical strain of heavy lifting increases pressure in the pelvic area, similar to the pressure created during straining for a bowel movement. People whose jobs or hobbies involve frequent heavy lifting should be particularly mindful of this risk.

Genetics may also play a role in who develops haemorrhoids. Some people appear to be predisposed to the condition, meaning they inherit a tendency toward developing haemorrhoids from their parents.^[4][7] If other family members have experienced haemorrhoids, an individual’s risk may be higher.

Engaging in anal sex can increase the risk of haemorrhoids by placing additional pressure and potential trauma on the anal area.^[7] Activities that regularly stress this region of the body can contribute to the swelling of veins over time.

Common Symptoms of Haemorrhoids

The symptoms of haemorrhoids vary depending on whether they are internal (forming inside the rectum) or external (developing under the skin around the anus). The location determines not only what symptoms appear but also how much discomfort they cause.

Internal haemorrhoids form inside the rectum where there are fewer pain-sensing nerves. Because of this, they rarely cause pain and people typically cannot see or feel them.^[1][2] Many individuals with internal haemorrhoids are completely unaware they have them. The most common sign of internal haemorrhoids is painless bleeding during bowel movements. People may notice small amounts of bright red blood on toilet paper, streaked on their stool, or dripping into the toilet bowl.^[1][2]

Sometimes internal haemorrhoids can push through the anal opening, a condition called prolapse (when an internal organ or tissue pushes through an opening).^[1][2] When this happens, people may be able to see or feel a small lump around the anus that can often be gently pushed back inside. Prolapsed haemorrhoids can cause pain and discomfort, and they may collect small amounts of mucus and tiny stool particles that irritate the surrounding skin.

External haemorrhoids form under the skin around the anus where there are many more pain-sensing nerves, making them considerably more noticeable and uncomfortable.^[2] Common symptoms of external haemorrhoids include itching or irritation in the anal area, pain or discomfort especially when sitting, hard lumps near the anus that feel sore or tender, swelling around the anus, and bleeding when wiping.^[1][2]

A particularly painful type of haemorrhoid occurs when a blood clot forms inside an external haemorrhoid. This is called a thrombosed haemorrhoid (a haemorrhoid containing a blood clot).^[1][2] When blood pools and clots in the vein, it causes severe pain that comes on suddenly. The clot creates a hard, discolored lump near the anus that may appear purple, blue, or black. Thrombosed haemorrhoids are typically much more painful than other types, though the clot only affects the anus and does not travel to other parts of the body.^[2]

Other symptoms people may experience include a lingering feeling that the bowel movement was not fully completed, mucus leaking from the anus, or difficulty cleaning the anal area after a bowel movement due to pain.^[4][6] The mucus discharge and incomplete cleaning can lead to further irritation and itching, creating a cycle of discomfort.

The appearance of haemorrhoids differs depending on the type. External haemorrhoids that are not thrombosed are usually the same color as the surrounding skin and feel soft to the touch. Thrombosed external haemorrhoids appear as firmer lumps with a blue, black, or purple color and are often significantly more painful.^[2] It is important to remember that not all lumps around the anus are haemorrhoids, so consulting a healthcare provider for an accurate diagnosis is essential.

Preventing Haemorrhoids Through Lifestyle Changes

Many cases of haemorrhoids can be prevented or their symptoms significantly reduced through simple lifestyle modifications and healthy habits. These preventive measures focus on reducing pressure on the rectal veins and maintaining regular, comfortable bowel movements.

One of the most effective preventive strategies is eating a diet high in fiber. Fiber helps soften stools, increases their bulk, and makes them easier to pass without straining.^[8][10] Good sources of fiber include fruits such as bananas, pears, strawberries, and avocados; vegetables like carrots, beets, broccoli, and spinach; whole grains and oats; legumes and lentils; nuts and seeds; and sweet potatoes.^[17] Healthcare providers recommend that adults consume between twenty-five and thirty grams of fiber daily, though most people eat far less than this amount.

When adding more fiber to the diet, it is important to do so gradually. A sudden increase in fiber intake can cause uncomfortable gas and bloating as the natural bacteria in the digestive system adjust to the change.^[8][10] People who struggle to get enough fiber from food alone may benefit from taking a fiber supplement such as psyllium or methylcellulose.

Drinking plenty of water and other non-alcoholic liquids throughout the day is equally important for preventing haemorrhoids.^[10][17] Adequate hydration works together with fiber to keep stools soft and easy to pass. Cutting down on alcohol and caffeine-containing beverages like tea, coffee, and cola can also help avoid constipation.^[6]

Developing good bathroom habits plays a crucial role in haemorrhoid prevention. People should respond promptly when they feel the urge to have a bowel movement rather than delaying or ignoring it.^[6][10] Putting off going to the bathroom can lead to harder stools that require more straining to pass. Similarly, spending no more than five minutes on the toilet helps prevent unnecessary pressure on the rectal veins.^[17] Reading or using electronic devices while on the toilet often leads to prolonged sitting and should be avoided.

During bowel movements, it is essential not to push or strain excessively.^[6][10] Straining increases pressure in the anal canal and pushes the haemorrhoids against the sphincter muscle. If a bowel movement does not happen naturally within a few minutes, it is better to leave the bathroom and try again later rather than continue straining.

Regular physical activity and exercise can help prevent haemorrhoids in several ways. Exercise helps maintain healthy bowel function and reduces the likelihood of constipation.^[6][18] It also helps with weight management, which is important because excess weight increases pressure on the pelvic veins. Additionally, exercise prevents prolonged periods of sitting, which can worsen haemorrhoids.

For people who must sit for extended periods due to work or other obligations, taking regular breaks to stand up and move around is beneficial.^[18][21] Standing up at least once per hour reduces the constant pressure on the rectal area. Some individuals find relief by using a donut-shaped cushion when sitting, which reduces pressure on haemorrhoids and provides added comfort.^[18]

People whose work involves heavy lifting should use proper lifting techniques and take care not to strain during the activity. When possible, getting assistance with heavy objects or using mechanical aids can reduce the risk of haemorrhoid development.^[2]

Maintaining good hygiene around the anal area is also important. People should wipe gently with soft, unscented toilet paper or use dampened wipes, wet tissue, or a bidet to clean themselves after bowel movements.^[6][17] Wiping too hard or too frequently can irritate existing haemorrhoids and make symptoms worse. Keeping the bottom clean and dry helps prevent additional irritation.^[6]

How Haemorrhoids Develop in the Body

To understand how haemorrhoids cause symptoms, it helps to know what happens in the body when these structures become problematic. Haemorrhoids are not actually varicosities (abnormally enlarged veins) in the traditional sense, but rather clusters of vascular tissue that include small arteries, small veins, and connections between them.^[5] These tissue clusters are cushioned by smooth muscle and connective tissue and are lined with the normal protective layer that covers the inside of the anal canal.

These haemorrhoidal cushions are present from before birth and persist throughout normal adult life as part of the body’s natural anatomy.^[5] They serve important functions in maintaining continence and protecting the anal canal. The tissues only become what we recognize as problematic haemorrhoids when they become swollen and inflamed.

The location where haemorrhoids develop determines their type and symptoms. The anal canal has an important landmark called the dentate line (a line marking the transition between two different types of tissue in the anal canal).^[5][11] Above this line, the tissue is supplied by nerves that sense less pain, while below the line, the tissue has many pain-sensing nerves. This explains why internal haemorrhoids that form above the dentate line are typically painless, while external haemorrhoids below the line can be quite painful.

When excessive pressure builds up in the blood vessels of the haemorrhoidal tissue, the vessels swell and become engorged with blood. The blood vessels involved must constantly work against gravity to return blood to the heart, which some researchers believe is part of why humans, as upright creatures, are prone to developing haemorrhoids.^[12][19]

Chronic constipation and repeated straining create a cycle that worsens haemorrhoids. Straining during bowel movements increases pressure inside the anal canal and pushes the swollen haemorrhoidal tissue against the ring of muscle that controls the anus.^[12][19] Over time, this repeated pressure can cause internal haemorrhoids to stretch and eventually prolapse through the anal opening.

The connective tissue that normally holds haemorrhoidal tissue in place can weaken with age or repeated stress. As this supporting framework weakens, the haemorrhoidal cushions lose their structural integrity and begin to bulge and sag.^[12][19] This is why haemorrhoids become more common as people get older.

When an external haemorrhoid becomes thrombosed, blood flowing through the swollen vessel slows down and begins to clot inside the haemorrhoid. The blood clot causes the sudden onset of severe pain because the clot stretches the skin covering the haemorrhoid, and this area has numerous pain receptors.^[1] The trapped blood also gives the thrombosed haemorrhoid its characteristic dark color. Eventually, the body breaks down the clot naturally, though this process can take several days to weeks. After the clot dissolves, it may leave behind a small flap of excess skin called a skin tag.^[3][12]

When internal haemorrhoids bleed, the blood typically appears bright red because it comes from arteries rather than veins.^[5] The rich blood supply to the haemorrhoidal tissue means that even small amounts of irritation can cause noticeable bleeding, though this bleeding is usually not dangerous.

Prolapsed internal haemorrhoids create problems beyond pain. When these haemorrhoids push outside the anal opening, they can collect small amounts of mucus and microscopic stool particles. This collection of material can cause an irritating condition that leads to constant itching around the anus.^[12][19] People may try to relieve the itching by wiping frequently, but this excessive wiping can actually worsen the irritation and create a frustrating cycle of discomfort.

The increased resting tone of the anal canal that researchers have observed in people with haemorrhoids means the ring of muscle around the anus is naturally tighter than normal, even when the person is relaxed and not having a bowel movement.^[12][19] This constant increased tension may contribute to reduced blood flow and increased pressure within the haemorrhoidal tissue, making symptoms more likely to develop and persist.