Far-right conspiracy theorists say 94% of US COVID-19 deaths don't count because those Americans had underlying conditions. That's bogus.

• The CDC's weekly report on US COVID-19 deaths breaks down fatalities by age, sex, race, and comorbidities — health conditions that increase a person's risk of a severe case.
• Because only 6% of Americans who died of COVID-19 had no preexisting conditions, some people think those are the only people who the virus has truly killed. That's false.
• Even President Trump retweeted, then deleted, once such erroneous statement.
• Health problems like diabetes and heart disease make COVID-19 more deadly. Those who die with comorbidities were still killed primarily by the virus, though.

Nearly 200,000 Americans have died of COVID-19.

The Centers for Disease Control and Prevention is working to track and study those deaths in as much detail as possible. Each week, the agency updates a provisional report that compiles coronavirus mortality data based on patients' death certificates.

The report breaks down US coronavirus deaths by age, sex, race, and location based on information submitted to National Center for Health Statistics. It also includes patients' comorbidities: preexisting health conditions like diabetes or kidney disease that are known to raise a person's risk of a severe infection.

The August 29 update to that report noted that in "6% of the deaths, COVID-19 was the only cause mentioned," meaning no other health conditions were "mentioned in conjunction with deaths."

That means only 6% of the 153,504 Americans who'd died by that date had no underlying health conditions.

But that line was widely misinterpreted — in fact, it set off a conspiracy-theory firestorm.

Countless social media users — including many associated with the far-right, pro-Trump conspiracy-theory group QAnon — suggested the report meant that only 6% of those counted in the US coronavirus death total actually died of the disease.

President Donald Trump even retweeted one such claim on August 30, then deleted it eight hours later. He also mentioned the 6% statistic in a September 1 interview with Fox News.

The tweet Trump reshared, posted by a QAnon supporter, said: "This week the CDC quietly updated the Covid number to admit that only 6% of all the 153,504 deaths recorded actually died from Covid. That's 9,210 deaths. The other 94% had 2 to 3 other serious illnesses and the overwhelming majority were of very advanced age."

But that's bogus.

Just because people had, say, heart disease or obesity doesn't mean the virus wasn't their cause of death. If they hadn't gotten COVID-19, those people would probably still be alive.

The CDC's report simply emphasizes how dangerous COVID-19 is for the many people who already have other health conditions.

In the weeks since the report with that line came out, Facebook, Twitter, and Instagram have flagged posts promoting this 6% idea as false information.

Underlying conditions increase the risk of severe coronavirus infections

Many preexisting health conditions put coronavirus patients at higher risk of developing severe cases. Overall, patients with underlying conditions were 12 times more likely to die of COVID-19 compared to otherwise healthy patients, according to CDC data collected through May 30. Similarly, a March report from Italy's National Institute of Health showed that at the beginning of the pandemic, 99% of COVID-19 patients who died there had at least one preexisting condition.

The CDC has found heart disease, lung disease, and diabetes to be among the most common comorbidities when COVID-19 kills.

Indeed, a study from Wuhan, China, showed that people with high blood pressure were twice as likely to die from COVID-19 as patients with normal blood pressure. Studies from Columbia University and Public Health England, meanwhile, found that obese people over 60 are more likely to require ventilation or die if they get COVID-19.

To think about how COVID-19 and underlying health conditions interact, think of a diabetic person's impaired immune system as a pot of water on a cold stove. If left alone, that pot won't overflow: The person is keeping the stove's flame off by managing their condition with insulin.

But now say the diabetic person gets the coronavirus — that turns the stove on, since high blood sugar impairs the immune system's ability to kill invading pathogens. A COVID-19 infection can also cause swelling in the body, which can lead to even higher blood-sugar levels. That in turn further compromises the body's immune response, allowing the infection to worsen.

Eventually, the pot might boil over.

But if this diabetic person hadn't gotten the coronavirus, they most likely would not have died.

That's what the CDC's recent COVID-19 mortality report showed. It was not in any way a revision of the agency's death count.

Underlying conditions are one reason the coronavirus has hit Black Americans disproportionately hard

The increased risk people with comorbidities face when they get COVID-19 in part explains why Black Americans are being hospitalized with and dying of the coronavirus in disproportionately high numbers.

The CDC estimates that Black Americans between the ages of 35-44 are 10 times more likely to die of COVID-19 than their white counterparts. According to data the agency published in April, 33% of the US's hospitalized coronavirus patients were Black, though Black people make up 18% of the overall US population.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, has said the coronavirus has hit Black communities hardest because of the prevalence of "underlying medical conditions — the diabetes, the hypertension, the obesity, the asthma."

Indeed, Black counties in the US have disproportionately high rates of underlying conditions like diabetes and heart disease, a May report showed. Those counties also experience more air pollution, which is linked to asthma.

These higher-than-average rates of underlying health conditions in Black communities are the product of systemic inequality.

One recent study found that "structural factors including healthcare access, density of households, unemployment, pervasive discrimination, and others," are driving COVID-19 disparities — and certainly "not intrinsic characteristics of Black communities or individual-level factors."

For instance, many Black, Latinx, and indigenous populations are at a higher risk of contracting COVID-19 simply because they're more likely to have to leave home for work: People of color make up about half of the US's 55.2 million essential workers.

Hilary Brueck and Canela López contributed reporting to this story.