Research suggests that red, tender or bleeding gums could trigger high blood pressure. In a review of 81 studies that included more than 250,000 people, U.K. scientists found that those who had moderate to severe gum disease (periodontitis) had a 22 percent higher risk for high blood pressure, and those with severe gum disease had a 49 percent higher risk.

Among people with periodontitis, systolic pressure (top number) was 4.5 mmHg higher and diastolic pressure (bottom number) was 2 mmHg higher, on average, than people without gum disease, the researchers found.

In five of the studies analyzed, researchers found that blood pressure dropped when periodontitis was treated. Blood pressure also dropped in patients treated for gum disease who didn’t have hypertension, they added.

When the gums are infected, the disease can spread to other parts of the body causing systemic inflammation, which can harm blood, the researchers noted. Some people may have a genetic susceptibility that might also play a part, along with other risk factors such as smoking and obesity.

More than 50 studies have shown that periodontitis is associated with increased risk for heart disease and an association between tooth loss and stroke, cardiovascular death and death from any cause.