What Causes Hemorrhoids in Adults?

What Causes Hemorrhoids in Adults?

Personally Researched | Last Updated: July 2026 | Based on Clinical Studies & Personal Experience.

Hemorrhoids are one of those topics nobody really wants to talk about, but almost everyone deals with at some point. 

If you've ever felt itching, discomfort, or noticed a bit of blood after a bowel movement, you're far from alone. In fact, hemorrhoids affect somewhere between 39 and 52 percent of adults. 

So what's actually behind them? Let's go through the real causes in simple terms, so you know what's going on and what you can do about it.

What Hemorrhoids Actually Are

Before we get into causes, it helps to know what hemorrhoids are in the first place. Hemorrhoids happen when the cushions of tissue and veins around your anus and lower rectum become swollen and shift out of place. 

Everyone actually has these tissue cushions naturally, they help with bowel control, but when they get irritated or stretched too much, they turn into what we know as hemorrhoids. 

They can form inside the rectum (internal) or right under the skin around the anus (external).

The Main Causes

Straining During Bowel Movements

This is the big one. When you push too hard to pass stool, especially if it's hard or dry, you put a lot of extra pressure on the veins around your anus. Over time, or even after just one hard push, that pressure can cause them to swell.

Chronic Constipation or Diarrhea

Both ends of the spectrum can be a problem. Constipation often leads to straining, while frequent diarrhea can irritate and inflame the area with repeated trips to the bathroom. According to NIDDK, chronic constipation or diarrhea are both listed among the leading causes of hemorrhoids.

Sitting on the Toilet Too Long

Scrolling on your phone while sitting on the toilet might feel harmless, but it isn't. Sitting for a long stretch, especially straining while you do it, adds pressure on the rectal veins, which can encourage hemorrhoids to form.

A Low-Fiber Diet

Fiber helps keep stool soft and easy to pass. Without enough of it, stool tends to become harder and more difficult to pass, which means more straining, and more risk of hemorrhoids.

Pregnancy

Pregnancy puts extra pressure on the pelvic area simply because of the growing uterus, and hormonal changes can also make veins more prone to swelling. Research on women with a history of childbirth (parous women) found a higher prevalence of hemorrhoidal disease compared to women who haven't given birth.

Aging

As we get older, the tissues supporting the veins around the anus and rectum naturally weaken. This is one of the reasons hemorrhoids become more common with age. A large study of Korean adults found that older age was independently linked to a higher chance of having hemorrhoidal disease.

Heavy Lifting

Repeatedly lifting heavy objects, especially without breathing properly, creates that same kind of straining pressure as pushing during a bowel movement, which can contribute to hemorrhoids over time.

Being Overweight

Carrying extra body weight increases pressure in the abdomen, which in turn adds pressure to the veins around the rectum. Some research has found that a higher body mass index is linked to a greater risk of hemorrhoidal disease, though the connection isn't seen consistently in every study.

A Sedentary Lifestyle

Sitting for long periods and not getting much physical activity is another commonly cited risk factor. Movement helps keep digestion regular and blood flowing well, so a lack of it can make hemorrhoids more likely.

Other Contributing Factors

Some studies have also linked hemorrhoids to smoking, high blood pressure, and family history. 

A study among Saudi adults found that the most common risk factors reported were a lack of regular physical activity, prolonged sitting during office work, and eating foods high in saturated fat, with a notable number of participants also having a family history of hemorrhoids.

Who's Most at Risk

While hemorrhoids can affect anyone, a few groups tend to be more prone to them:

• Adults over 50, since tissue support naturally weakens with age
• Pregnant women or those who've recently given birth
• People with chronic constipation or diarrhea
• People with desk jobs or who sit for long stretches
• People who don't get much dietary fiber
• People with a family history of hemorrhoids

Interestingly, one large study found hemorrhoidal disease was slightly more common in women overall, though other research has found the opposite depending on the population studied. The truth is, risk really comes down to a mix of lifestyle, genetics, and everyday habits, more than gender alone.

How to Lower Your Risk

Fortunately, many of the causes above are things you can actually influence:

Eat more fiber. Fruits, vegetables, whole grains, and beans help keep stool soft, so you don't need to strain.

Drink enough water. Staying hydrated works hand-in-hand with fiber to keep things moving smoothly.

Don't linger on the toilet. Go when you need to, and don't sit there longer than necessary.

Stay active. Regular movement supports healthy digestion and circulation.

Watch your lifting technique. Exhale as you lift instead of holding your breath and straining.

Respond to the urge to go. Holding it in can lead to harder stool and more straining later.

When to See a Doctor

Most hemorrhoids are manageable with simple lifestyle changes and don't require anything more serious. 

That said, it's worth seeing a doctor if you notice ongoing bleeding, a lump that doesn't go away, persistent pain, or if your symptoms just aren't improving. 

These same symptoms can sometimes point to other digestive conditions, so getting checked out is always the safer choice.

Conclusion

Hemorrhoids are incredibly common, and in most cases, they come down to everyday habits: straining, sitting too long, not getting enough fiber, or not moving enough. 

Add in factors like pregnancy, aging, or genetics, and it's easy to see why so many adults deal with them at some point. 

The upside is that a lot of these causes are within your control. Small changes, more fiber, more water, more movement, and less straining, can go a long way in preventing hemorrhoids or easing the ones you already have. 

And if things don't improve on their own, a doctor can help you find the right next step.

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• 5 Donut Pillows that Help with Hemorrhoids.
• 7 Best Hemorrhoid Squatty Potty Toilet Foot Stools.
• 10 High-Fiber Foods That Relieve Constipation Naturally

📚 Medical Sources

1. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) — Hemorrhoids: Symptoms & Causes. 
2. NIDDK — Hemorrhoids: Definition & Facts. 
3. NIDDK — Eating, Diet, & Nutrition for Hemorrhoids. 
4. Cleveland Clinic — Hemorrhoids: Symptoms, Causes & Treatment. 
5. Riss, S., et al. (2012) — The prevalence of hemorrhoids in adults. International Journal of Colorectal Disease, 27(2), 215–220. 
6. NIDDK — Hemorrhoids.
7. Johanson, J.F., & Sonnenberg, A. (1990) — The prevalence of hemorrhoids and chronic constipation. Gastroenterology, 98(2), 380–386.
8. Lohsiriwat, V. (2012) — Hemorrhoids: From basic pathophysiology to clinical management. World Journal of Gastroenterology, 18(17), 2009–2017. 
9. Alonso-Coello, P., et al. (2006) — Fiber for the treatment of hemorrhoids complications: a systematic review and meta-analysis. American Journal of Gastroenterology, 101(1), 181–188.