Getting COVID Could Increase Your Risk of Developing High Blood Pressure

New research suggests that having COVID-19 may pose a greater risk of developing longer-term high blood pressure than the flu.

The study, published earlier this month in the journal Hypertension, investigated whether people with COVID or influenza had higher rates of hypertension six months post-infection. Researchers found that both hospitalized and non-hospitalized COVID patients were significantly more likely to develop hypertension than flu patients, some of whom had hospital visits and others who didn’t.

Previous studies have linked both COVID and influenza with high blood pressure—also known as hypertension. Here, researchers wanted to learn about “the incidence and risk factors associated with new-onset hypertension” in people with these respiratory illnesses, they wrote in the study.

Defined by the American Heart Association as a blood pressure reading of 130/80 mm Hg or higher, hypertension can lead to heart disease, stroke, and other major health issues. The condition contributes to or causes nearly 8 million deaths a year worldwide. 

Meanwhile, global COVID cases have topped 769 million, per the World Health Organization.

The study “statistics are alarming given the sheer number of people affected by COVID-19 worldwide,” lead study author Tim Duong, PhD, a professor of radiology at Albert Einstein College of Medicine and Montefiore Health System in New York City, told Health. “This high incidence of persistent hypertension is not limited to people with severe COVID-19 illness.”

Luke Laffin, MD, co-director of the Center for Blood Pressure Disorders at Cleveland Clinic, told Health that the study provides another “piece in the puzzle” regarding COVID infections and cardiovascular disease. Still, he said, researchers need more information to determine the actual risk of post-COVID hypertension.

For the study, researchers analyzed medical records from New York City’s Montefiore Health System, which serves a racially and ethnically diverse population. The study involved about 45,000 people with COVID between March 2020 and August 2022 and 14,000 who had the flu between January 2018 and August 2022. No patients had a history of hypertension. 

The researchers reviewed which patients had high blood pressure at a six-month follow-up appointment. They found that about 20% of people hospitalized with COVID and 11% non-hospitalized patients had high blood pressure six months later. That’s compared to 16% of hospitalized flu patients who developed hypertension and 4% of non-hospitalized people with the flu who had hypertension post-infection.

In addition, the researchers found that Black people, men, and those over 40 had the highest risk of persistent hypertension post-COVID. It was also more common for people with preexisting health conditions, such as coronary artery disease and chronic obstructive pulmonary disease (COPD), to develop high blood pressure.

Laffin said the study had a significant limitation: The researchers couldn’t factor in the effect of COVID vaccines on blood pressure readings because they weren’t available then. “Theoretically, this may impact their risk [by] lessening the downstream effects of COVID,” he explained.

Researchers also don’t know why a COVID infection may influence blood pressure risk, but Laffin theorized that it could be related to factors such as persistent inflammation, a long-term impact on the immune system, or damage to the endothelial cells lining blood vessels.

Another unknown is whether any potential COVID-related high blood pressure can disappear over time. “We don’t have enough data to say yes or no,” Laffin explained. “Most people that develop hypertension can lower their blood pressure with lifestyle interventions alone; however, that may not be enough to reach suggested blood pressure targets.”

The best way to reduce your chances of COVID-related complications (including possible high blood pressure) is to take precautions to prevent contracting COVID in the first place. Measures such as frequent hand washing and avoiding close contact with infected people can help reduce your risk.

Getting vaccinated can also lower your risk of infection and reduce your chances of having long-term side effects if you do test positive for COVID, said Duong.

According to Laffin, it’s too early to say whether COVID treatments such as Paxlovid, the antiviral prescribed for people at risk of severe illness, could influence whether people develop high blood pressure after an infection.

If you do contract COVID, Duong advised starting a dialogue with a healthcare provider about the possibility of developing hypertension, especially if you fall into any high-risk categories identified in the study.

“These findings hopefully could heighten awareness to screen at-risk patients for hypertension after COVID-19 illness,” said Duong. “Earlier identification of patients at risk would enable treatment for hypertension and hypertension-related complications.”