What Can Your Farts Tell You About Your Health?

Everybody toots, and that's okay. But sometimes passing gas can signal more serious health issues.

By Jocelyn Solis-Moreira
Dec 8, 2023 1:30 PM
woman wearing glasses holding her nose from a smelly fart
(Credit: UfaBizPhoto/Shutterstock)


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What do the president of the United States, Harry Styles, and your next-door neighbor all have in common? Farts. 

Whether you find farting improper or you’re someone who isn’t afraid to let it rip, everyone cuts the cheese one way or the other. 

While farting is often seen as embarrassing, it's actually a healthy sign of digestion and can even provide insights into our overall health. So, whether you're someone who discreetly passes gas or lets it out with pride, it's worth paying attention to this common yet often overlooked bodily function. Your farts, especially if they're unusually smelly, might just be signaling it's time to check in with a healthcare professional.

Why Do We Fart?

Your body is designed to fart, and you can expect an average of 10 to 20 farts per day, says Harvey Hamilton Allen Jr., a gastroenterologist at Digestive Disease Medicine of Central New York. 

He says the human body can hold up to 1,500 milliliters of intestinal gas; that’s almost the size of 6 cups of water.

“Studies have shown that people perceive that they're passing a lot of gas," says Allen. "But pretty much people before and after they eat have an equal amount of gas. So it’s just the perception that this is abnormal."  

Is Farting Good for You?

Yes, farting is good for you. It is a natural by-product of your digestive system that lets you know your food has been properly digested. But farts are more than White Castle’s revenge; they can also act as a treasure trove of medical secrets. 

Read More: Stomachache? Your Gut Bacteria Might Be to Blame

Why Do My Farts Smell So Bad?

If your farts have a particularly strong or unpleasant odor, it could be due to several factors, often related to diet or digestive health. Here are some common reasons for bad-smelling flatulence:


Certain foods that are high in protein, sulfur, or fiber can lead to smelly gas when broken down in the gut.

Medical Reasons

Your farts could also smell bad for medical reasons such as different types of medication, infection, or constipation.

What Does It Mean When You Fart a Lot?

Farting a lot, or excessive flatulence, can be influenced by several factors. Whether you’re passing gas from the attic or the basement, your smelly, frequent, or loud farts may be signs of an underlying health condition. Here are some common reasons why someone might fart more than normal.

1. You Might be Pregnant   

If you’re frequently tooting your horn, it could be a sign of pregnancy. When you’re pregnant, your body goes into overdrive producing many hormones, including progesterone. Progesterone helps to create the lining of the womb and maintain it throughout pregnancy. That’s because progesterone wears many hats and also acts as a smooth muscle relaxant. Increased progesterone can relax and slow down the digestive tract. 

Why Do Pregnant Women Fart a Lot?

Inessa Khaykis, a gastroenterologist at Vanguard Gastroenterology in New York, says that excess gas during pregnancy could also come from the baby pressing on the intestines as it expands during pregnancy. “[Those are] just one of the symptoms that could be associated with abdominal distension and excessive gas production," she says. "Bacterial overgrowth and some parasitic infections are other conditions that can lead to accumulation of fluid in the abdomen that also could exert pressure on the digestive tract.”

 2. You’re Lactose Intolerant 

Lactose intolerance is another reason for excess gas. Even if you’ve never had trouble eating dairy before, chances are you’ll probably get it as you age. By age 20, 30 million Americans become lactose intolerant, and about 65% of the entire human population has a reduced ability to digest lactose after infancy. 

Why Dairy Makes You Fart

Dairy products are broken down by an enzyme known as lactase, but the body makes less of this protein after our early days. Low lactase levels make it hard to digest, and then it gets passed along to the bacteria-populated colon. These bacteria end up breaking down the lactose, but at a cost. “The bacteria have a picnic at our expense with all the fermentation and gas production that goes on after,” says Khyakis. 

3. Your Mental Health Is Taking a Toll 

If you’re feeling anxious before your big meeting at work, the butterflies in your stomach may actually be gas. Scientists have recently found a connection between mental health and gas production. One study presented at UEG Week Virtual 2021, a European gastroenterology conference, found that extreme burping and farting are associated with stress, anxiety, and depression symptoms.  

Does Anxiety Cause Farting?

According to the American Psychological Association, stress and anxiety tense up your muscles in response to an impending threat. Your tensed-up muscles include the stomach muscles, causing a slowdown in digestion. Not processing your food efficiently makes it pass more slowly, resulting in a gassy stomach. Additionally, stress makes it harder to swallow food and may increase the amount of air in each swallow. The outcome is an increase in burps and farts. 

4. You Might Have a Disease 

There’s nothing abnormal about farting. But if you’re breaking wind and feeling pain from doing it, it could be a sign of cancer. This is because cancer can build up gas in the digestive tract, making you pass gas more often. 

Is Farting a Sign of Cancer?

One of the signs of stomach cancer is excessive farting paired with abdominal pain, bloody vomit, and bad breath. Pancreatic cancer creates indigestion and makes it difficult to break down food and absorb nutrients, causing gas and bloating problems. Colon cancer and Crohn’s disease can block your intestines and cause gas to build up. 

Does Crohn's Disease Cause Farting?

People with Crohn’s disease frequently have trouble with their small intestine absorbing nutrients from food. Undigested food makes its way to the colon, where gas-producing bacteria feast. Additionally, severe Crohn’s disease may make you susceptible to bacterial overgrowth, changing the makeup of the gut microbiome. One study found people with Crohn’s disease and excess bacteria in the small intestine had 75% more farts than people who did not. 

5. It’s Just a Sign of Old Age 

In short, as you age, you’re more likely to develop health problems that predispose you to produce more gas. 

Do Patients Fart After Surgery?

While older adults have recently been getting less abdominal surgery, people who need surgery to repair hernias and bowel disease are at risk for sticky bands of tissue known as abdominal adhesions. Khaykis says adhesions slow down the intestinal tract. The relaxed intestines can lead to an overgrowth of intestinal bacteria in the gut microbiome. The more vibrant bacterial population you have, the more gas bacteria can produce. 

Is Farting a Sign of Diabetes?

Another potential reason is diabetes. The risk of diabetes increases as you get older, and an unintended consequence is increased flatulence. “As we get older, people develop diabetes, and they can take medications for other health-related issues that might slow down their digestive system," explains Khaykis. "That can change the gut flora, which can lead to excessive gas production. 

Read More: Time-Travelling Stool Could Address Diseases Linked to Your Gut

Is It Bad to Hold in Farts?

Holding in farts occasionally is generally not harmful. The anal sphincter, which surrounds the anus and rectum, provides control over the release of gas and stool. By tightening this muscle, one can delay passing gas until a more appropriate time or location. 

However, frequently suppressing flatulence can lead to certain digestive symptoms. While it's a common and often necessary practice in social situations, it's important to release the gas when it's convenient to avoid discomfort or potential digestive issues.

Read More: Is Something in Your Diet Screwing With Your Stomach?

When Is Farting a Lot Bad?

When in doubt, you may want to see your doctor if something doesn’t feel right. “If something is bad or perceived as being off, it is just safer to check because a lot of underlying medical conditions can present very similarly," says Khaykis. "So, your doctor can sift through additional signs and symptoms to arrive at the right diagnosis." 

How Much Farting Is Too Much?

Allen agrees that you should not hesitate to see your doctor if the roar from your rear is changing your quality of life. While most people with abdominal discomfort feel better when they pass a little gas, red flags should go up in your head if you also experience severe diarrhea, vomiting, abdominal tenderness, nocturnal abdominal pain and rapid weight loss. 

How to Stop Farting   

Most of the time, farting is normal and just another part of our smelly existence. But if you don’t want to doom yourself to rotten egg-like farts for the rest of your life, Allen says there are ways to minimize gas production. 

Watch What You Eat

Most excess and foul gas comes from the food you eat. Limiting certain foods may help pinpoint the cause behind your bottom burp. For example, milk products and sugar-free candies with sorbitol — also found in fruits such as peaches and apples — can make you gassy. Whereas foods such as chicken, onions, and coffee tend to have odorous gases because of a naturally smelly compound known as sulfur.   

Read More: Farts: An Under-appreciated Threat to Astronauts

Limit Smoking and Gum Chewing

Gas can also be a result of swallowing too much air. “Most people swallow a lot of air if they eat too fast or gulp their food," says Allen. "Smoking and chewing gum [also] increases swallowing, and that’s a very common thing." 

Still, farting is unavoidable, and you shouldn’t entirely cut out gas-producing foods like broccoli and beans just because they make you cut the cheese a bit more than usual.  You’re going to fart, and that’s okay. Even if you find it embarrassing, it's good to remember that farting is as natural as breathing. 

Frequently Asked Questions About Farting

Why Do Beans Make You Fart?

Beans contain high amounts of fiber and a non-digestible carbohydrate called raffinose. The human body lacks the enzymes needed to properly digest them. When beans reach the large intestine, the bacteria there start fermenting them, producing gas as a byproduct. This increased gas production can lead to more farting after consuming beans.

Why Do I Fart So Much at Night?

Farting at night may be attributed to the body's relaxed state during sleep. The muscles, including those in the digestive tract, relax, facilitating the movement of gas. Additionally, the accumulation of gas from foods eaten throughout the day can contribute to increased flatulence during the night. Lying down also changes how gas moves through your intestines, potentially leading to more farting.

Why Do My Farts Smell Like Sulfur?

The sulfur-like smell in farts is often due to consuming foods high in sulfur. Foods like eggs, meat, and cruciferous vegetables (like broccoli, cauliflower, and cabbage) contain sulfur compounds. When digested, these compounds are broken down by gut bacteria, producing hydrogen sulfide, a gas that has a distinct sulfur-like odor.

Why Do My Farts Smell Like Sewage?

Farts smelling like sewage can be due to a combination of factors. High-sulfur foods, as mentioned, contribute to this odor. Additionally, if food is not properly digested (due to digestive disorders or imbalances in gut bacteria), it can ferment in the gut, producing foul-smelling gasses. Another factor could be the presence of certain bacteria in the gut that produce more pungent gasses. If this issue is persistent and accompanied by other symptoms, it may be worth consulting a healthcare professional.

Read More: Gut Bacteria's Role in Anxiety and Depression: It’s Not Just In Your Head

This article was originally published on Nov. 16, 2021 and has since been updated by the Discover staff with new information.

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