President Donald Trump tweeted early Friday that he and his wife, Melania, had tested positive for COVID-19, the illness that has killed more than 207,000 Americans and that he has tried to downplay in his public remarks. According to the White House, the president will spend “the next few days” at the Walter Reed National Military Medical Center, taking him off the campaign trail, at least temporarily, just 32 days before the election.

Though the first lady tweeted that she and her husband were “feeling good," the White House later confirmed that both Trumps had “mild symptoms.”

Here are answers to some questions you may have.

What are the president’s risk factors for serious illness?

Although he said he was in great health after his latest physical exam, the president’s age, 74, and weight, which qualifies as obese, put him at high risk.

According to the new vaccine allocation plan from the National Academies of Sciences, Engineering, and Medicine, people age 65 and up account for about 80% of reported COVID-19 deaths. Many of them already had age-related chronic illnesses that have damaged their lungs, heart, blood vessels, and kidneys — organs that COVID-19 can attack. Even in healthy seniors, immune function tends to diminish.

The mortality rate for infected people age 70 and up is estimated to be about 5%, according to the Centers for Disease Control and Prevention.

Obesity — defined as a Body Mass Index of 30 or more (174 pounds for a 5-foot-4 woman) — is a risk factor that transcends age. A French study of COVID-19 patients in intensive care found those with a BMI over 35 had a sevenfold higher chance of needing mechanical ventilation than those with a BMI in the healthy range. A study of COVID-19 patients under age 60 who were hospitalized in New York City found that a BMI over 35 almost quadrupled the chance of needing critical care.

Exactly why is not clear, but the virus appears to exploit a number of weight-related abnormalities, as explained in a review of eight studies published recently in the journal Endocrinology, Diabetes and Metabolism.

Being male is also a risk factor for more serious cases of COVID-19. White people have been at lower risk, but it’s hard to know how much of that is behavioral or socioeconomic.

When was he likely exposed to the virus?

It is hard to know for sure, but the president announced his own positive test on Twitter hours after having tweeted that his close aide Hope Hicks had tested positive. Trump has refused to wear masks at all but a few events, and has expressed skepticism about the effectiveness of face coverings.

Does the president have any symptoms?

Symptoms usually develop within 2 to 14 days of being exposed, typically about 5 days. The president has had what one person described as cold-like symptoms. Another person said he seemed “lethargic” at a fund-raiser he attended at his golf club at Bedminster, N.J., on Thursday. By Friday afternoon, White House Chief of Staff Mark Meadows spoke to reporters — maskless — and confirmed that the president did have “mild” COVID-19 symptoms.

On Thursday night, a White House official said the president’s treatment plan was still being discussed, as was the idea of a national address or a video-recorded statement to show the president is functioning.

What is the recommended treatment for people with mild disease?

For most people, the answer is simply watching and waiting. No medicines have been approved for COVID-19 patients who are not sick enough to be hospitalized, said John J. Zurlo, chief of the division of infectious diseases at Thomas Jefferson University.

But Trump was given an experimental drug containing monoclonal antibodies — potent immune-system proteins that were derived from the blood of patients who had recovered from the disease. Such drugs are still being tested, but early results are promising.

Among the few approved drugs shown to help against COVID-19 so far is remdesivir, which is normally given intravenously in a hospital, Zurlo said. The other main category of medicines proven to help some COVID-19 patients is corticosteroids, but again, those would be given to someone in a hospital, to treat the inflammation that is a hallmark of severe disease. If given to a patient with mild symptoms, steroids can make the disease worse, as they tamp down the immune response, Zurlo said.

David Cennimo, an assistant professor of medicine at Rutgers New Jersey Medical School, said that based on the symptoms that have been reported so far, he would order rest and continued monitoring for respiratory symptoms.

Might Trump progress to serious disease, and how quickly?

Despite a growing body of studies, COVID-19 remains little understood and unpredictable. United Kingdom Prime Minister Boris Johnson had mild symptoms after announcing his infection on March 27. About a week later, on April 6, Johnson was rushed to a London hospital for intensive care. He spent a week in the hospital and received oxygen treatment but was not put on a ventilator.

An analysis of about 1,000 Chinese patients with mild to moderate disease who were followed for 28 days found that 71% recovered or were stable, 22% progressed to severe disease, 2% progressed to critical illness and 4% died. The risk factors for progression were older age, being male, hypertension, diabetes, chronic pulmonary disease and coronary artery disease.

In some reported cases, patients seem to be recovering, then suddenly take a turn for the worse.

Neil Fishman, an infectious diseases specialist at the University of Pennsylvania, said even some old people defy expectations: “I’ve seen healthy 50-year-olds wind up on ventilators tor six weeks, and I’ve seen 80-year-olds just get a few sniffles.”


What is contact tracing and how is it being used in the president’s case?

When someone tests positive, a public health worker known as a contact tracer calls them to ask questions about where they went and whom they came into contact with in the previous two weeks, which is how long the virus can take cause symptoms. Those contacts are notified they may have been exposed and should self-quarantine and monitor for symptoms.

In Trump’s case, his carefully coordinated schedule makes it easy to know where he has been in recent weeks, but it may be impossible to track down everyone he came into contact with since he encounters so many people, even during a day that he stays in the White House.

“There are a couple hundred people who call his home their office,” said Rutgers’ Cennimo.

In July, White House Press Secretary Kayleigh McEnany said Trump is tested for the virus “multiple times a day.” That could be helpful in quickly tracing his contacts, Cennimo said, by narrowing down the time frame and the number of people he saw while potentially infectious. Most people are not tested until they develop symptoms or believe they were exposed to the virus.

Everyone in his inner circle is being tested, and so far, most have been negative. Among the negatives are the president’s youngest son, Barron; eldest daughter and adviser Ivanka; and White House senior adviser and Trump son-in-law Jared Kushner, according to U.S. News and World Report.

Former Vice President Joe Biden, the Democratic nominee for president, tweeted on Friday that he and his wife had tested negative.

However, diagnostic testing only provides a snapshot in time and the test is not perfectly accurate, so the test needs to be repeated to rule out an infection.

Staff writers Sarah Gantz, Tom Avril, and Stacey Burling contributed to this article.