These underlying conditions make coronavirus more severe, and they're surprisingly common

A wide array of people are at risk, including those with high blood pressure and diabetes. Here's how they can prepare.


Doctors look at a lung CT image in a hospital in Yunmeng County, Xiaogan City, in China's central Hubei Province.

High blood pressure, diabetes, and cardiovascular disease are so commonplace that everyone reading these words likely knows somebody with at least one of these maladies.

They are also the “underlying conditions” most associated with severe cases of COVID-19, based on early clinical profiles on the disease. Even though 80 percent of COVID-19 cases are mild, these reports reveal that the novel coronavirus can endanger people other than the elderly and infirm.

The idea that the virus only poses a threat to older people comes from focusing too heavily on COVID-19’s death rate, which the World Health Organization updated last Wednesday to 3.4 percent. This rate is an average across ages, and the chances of dying do rise among older people.

But evidence also shows that COVID-19 is more fatal across all age groups than seasonal influenza, with death rates six to 10 times higher for those under 50. Moreover, death isn’t the only danger, and severe cases of COVID-19 are more common among young adults than you might think.

A study published February 28 in the New England Journal of Medicine, for example, examined the age breakdown for 1,099 coronavirus patients. The majority of non-severe cases—60 percent—are teens and adults between 15 to 49 years old, which might suggest this group is spared the worst of the virus.

In truth, severe cases were slightly more abundant among this younger demographic. Of the 163 severe cases reported in the study, 41 percent were young adults, 31 percent were aged 50 to...

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