It’s highly likely that poor oral health is linked to heart disease. Studies have shown that people with unhealthy mouths suffer more heart attacks and have an increased risk of stroke compared to people with good oral health.

Specifically, we’re referring to gum health. What does the state of your gums have to do with your heart? The common factor is inflammation. In the case of gum disease, there are two types: gingivitis, a disease where the gums are sore, swollen and red, and the more serious periodontitis, where swollen gum tissue pulls away from the teeth.

Between one-third to one-half of Americans have some form of periodontitis, according to the Centers for Disease Control and Prevention. But don’t rely on warning symptoms to alert you to the fact that you have the disease. Many people with mild to moderate gum disease don’t suffer any symptoms.

So what’s the relation to heart disease? Inflammation is central to the process that causes the buildup of fatty plaques in the arteries that feed the heart. These plaques cause the blood vessels to harden and narrow. As fat deposits in the arteries, white blood cells are attracted to the area and they form a key component of the plaques that can eventually block arteries and starve the heart and brain of oxygen.

Bacteria play a role in heart disease, too. Studies have implicated the same bacteria that cause gum disease as a culprit in strokes and heart attacks. Gums are very vascular, meaning every time you brush your teeth, bacteria from your mouth can enter the bloodstream and cause inflammation.

In a study published in 2015, researchers studied 112 people who suffered a heart attack. They found that periodontitis was a risk factor for death from heart attacks. Those findings back up recommendations published jointly by the Journal of Periodontology and the American Journal of Cardiology in 2009.