(CNN)As the novel coronavirus sweeps the globe, people with high blood pressure are among those who are at heightened risk for more severe complications should they contract Covid-19.
"If you get an extraordinary viral disease that will damage your lungs, you need a heart that can work with how your body responds to the virus," said Dr. Maria Carolina Delgado-Lelievre, an assistant professor of medicine at the University of Miami's Miller School of Medicine.
But for those with hypertension, "Covid will cause a systemic reaction in the body in a patient that already has risk" because of poor heart health, she said. That means the virus can attack multiple organ systems.
The CDC's Morbidity and Mortality Weekly Report from February 12 to March 28 showed that 9% of Covid-19 patients in the United States also self-reported a diagnosis of cardiovascular disease.
High blood pressure is the most common type of heart disease and affects almost half of all American adults, according to the CDC. That's about 108 million Americans living with the condition.
And because hypertension is more common as people grow older, that means many of the same people with high blood pressure already overlap with the elderly population
s known to be at higher risk for contracting Covid-19.
Recognize the warning signs and know how to take your blood pressure
At a basic anatomic level, hypertension happens when there's an abnormality in blood vessels that can impair the way oxygen is transferred to the cells.
Having a low blood oxygen level is common among those hospitalized with Covid-19, according to a study of patients in Wuhan, China published in the Lancet in January.
"High blood pressure is not [just] a number. The number