Constipation can make you feel bloated and uncomfortable, but a new study suggests it might also be linked with a more serious and unexpected health outcome: major cardiac events.

The research specifically found a link between people who have constipation and a higher risk of severe cardiovascular problems, such as heart attacks and strokes, especially if they also have high blood pressure. 

“Traditional cardiovascular risk factors such as high blood pressure, obesity, and smoking have long been recognized as key drivers of heart disease. However, these factors alone do not fully explain the occurrence of major cardiac events,” study author and head of the Hypertension Research Group at Monash University, Francine Marques, PhD, told Health. “The gut microbiome is now a well-known risk factor for heart disease, and constipation influences it.”

While this isn’t the first study to suggest a connection between constipation and cardiovascular events, experts said more research is needed to understand the relationship between the two. In the meantime, here’s what scientists do know—and whether you should worry if you’re frequently constipated.

In recent years, evidence has shown a connection between the gut microbiome and heart health, prompting scientists to examine how constipation might factor in. 

In 2023, one study found “suggestive causal associations” between constipation and atrial fibrillation, which is the most common type of heart arrhythmia. However, it didn’t see a link between constipation and heart failure, stroke, or coronary artery disease. Another 2023 study found the opposite—that for hospital patients over 60 years old with both constipation and hypertension, the risk for all cardiovascular events was higher.

Against this backdrop, researchers set out to further investigate the interplay between constipation and heart conditions. For the most recent study—published in the American Journal of Physiology-Heart and Circulatory Physiology—scientists analyzed data from over 400,000 people aged 40 to 69, compiled in the U.K. Biobank, a large biomedical database and research resource. 

They reviewed medical records, surgical histories, and death register data to find any associations between constipation and major adverse cardiac events (MACE) like heart failure, ischemic stroke, or acute coronary syndrome. Constipation was defined as routinely consuming laxatives or being noted on hospital medical records or questionnaires for irritable bowel syndrome.

After adjusting for age, sex, BMI, use of medication that may cause constipation, smoking status, and health conditions like high cholesterol and diabetes, the team discovered that those with constipation had a two to threefold increased risk of having a major adverse cardiac event compared to people with normal bowel habits. The study also revealed that constipation in patients with high blood pressure raised the risk of a cardiac event by about 1.7 times.

“We identified constipation as a potential risk factor independently associated with higher MACE prevalence,” the authors wrote.

Constipation shared between 21% and 27% of genetic risk factors for cardiovascular disease, which the authors said could explain the link between the two. For example, genes could be to blame for “disturbances” in the autonomic nervous system, which regulates both cardiovascular and GI functions.

In a different study, researchers theorized that straining during bowel movements could cause a spike in blood pressure, which, over time, could potentially trigger cardiovascular events.

If you experience constipation, experts say there’s no need to jump to conclusions about your heart health. While the new research suggests a possible association between constipation and heart problems, no studies have established that one causes the other.

“There’s absolutely no causality,” said Timothy Ritter, MD, gastroenterologist and senior medical director at GI Alliance Research, in regard to the most recent study. “People that have constipation may have any other issues going on that put them at high risk for cardiovascular disease.”

The study has several other limitations, including that it only included participants of white European ancestry, which means the findings may not be broadly applicable. Some of the data was also self-reported—and thus may be inaccurate. And Ritter told Health that “constipation” was not well defined: Did people use a “laxative every day, or just once a month, during menstruation?”

The intermittent nature of constipation also makes it difficult to assess any relationship it might have with heart health, said Mary Branch, MD, a cardiologist in Greensboro, North Carolina. “So if you’re trying to find a link with an outcome with something that is so transient and not a definitive disease state,” she told Health, “that becomes a little bit messy to come up with a conclusion.”

Because research is ongoing, Branch said, “it’s hard to know whether trying to regulate [constipation] would help reduce your risk of cardiovascular disease.”

However, there is a clear link between your gut microbiome and cardiovascular disease because of its role in managing inflammation, Branch said. “Fiber improves gut function, helping us avoid constipation, and also improves blood pressure, minimizing the risk of heart disease,” Marques said. “We recommend that independent of the presence of constipation, people increase their dietary fiber intake because most people are fiber-deficient.”

Branch also suggested prioritizing your overall heart health by following the American Heart Association’s guidelines. That means getting consistent physical activity, following a diet filled with whole foods, prioritizing sleep, controlling cholesterol, and refraining from smoking.

“People want to find something new and sexy—a quick fix—but it just doesn’t exist,” Branch said. “It’s really just about consistent, good habits.”