Medication and a thermometer for checking symptoms of coronavirus, cold, and flu.

With the novel coronavirus spreading rapidly in the U.S., it’s understandable that people who develop a cough or fever might wonder whether they have COVID-19, the disease caused by the virus.

Many people may think they have the disease, even if their symptoms are more consistent with other health problems, like a cold or the flu, says Gary LeRoy, M.D., a family physician in Dayton, Ohio, and president of the American Academy of Family Physicians. 

Contributing to the confusion is that this is a rapidly evolving situation, where what is known about the disease changes by the day, even by the hour, LeRoy and other experts say. 

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The result: “Minor respiratory symptoms that otherwise people would dismiss are causing a lot of anxiety,” says Michael Hochman, M.D., director of the Gehr Family Center for Health Systems Science and Inno­va­tion at Keck Medicine of USC in Los Angeles.  

In addition, testing for the virus is still not widely available, making it difficult for people to know for certain when they are infected.

But some facts are clear: COVID-19 is a viral respiratory illness, with common symptoms of fever, dry cough, and, sometimes, shortness of breath. These range from mild to severe, and the most serious cases are potentially fatal, particularly in people who are older or have underlying medical conditions.

And like other viral respiratory illnesses, it’s thought that this new disease spreads primarily through close contact with an infected person, through the droplets produced during coughs or sneezes, according to the Centers for Disease Control and Prevention.

“This is definitely a situation we should be taking seriously,” Hochman says. “But panicking isn’t helpful.” Carefully evaluating your symptoms, risk factors, and known exposure can help you decide when you can treat at home, when you should be tested, and whether you should contact a doctor. 

Cold, Flu, or COVID-19?

Currently, three respiratory diseases caused by viral infection are circulating in the U.S., according to LeRoy: the common cold, the flu, and COVID-19.

It can be hard to distinguish among them because some symptoms overlap and others can vary substantially from person to person. Still, each of these infections tends to have certain defining characteristics that may give you some helpful clues. 

Colds. These viral infections typically come on gradually, according to LeRoy, with runny nose, congestion, sore throat, and cough usually at their worst three or four days after onset. Colds can sometimes also cause headaches, body aches, and fever, but they’re generally milder than those associated with the flu.

Flu. This infection is notable for coming on fast and causing high fever, severe body aches, and extreme fatigue. Often, “it has a very sudden, abrupt onset,” LeRoy says. “It’s like a train hit you.” Occasionally, the flu can cause vomiting and diarrhea, but this is more common in children. 

COVID-19. Fever, dry cough, and less often, shortness of breath, are the major tip-offs. According to a World Health Organization analysis of 55,924 patients, people infected with the new virus developed a fever in 88 percent of cases, a dry cough in 68 percent, and shortness of breath in 19 percent. Symptoms tend to appear two to 14 days after exposure to the virus, according to the CDC.

The cough may be persistent, without easing at all throughout the day, LeRoy says. People sometimes report being unable to catch their breath or to breathe or talk easily, or may feel out of breath after minor exertion, like walking around the house.

We're learning that a variety of other symptoms may also come with this disease, sometimes appearing before cough and fever.

For instance, more than 35 percent of people reported body aches and almost 15 percent said they experienced chills in a new analysis of healthcare workers in King County, Wash.—the nation's first coronavirus hot spot—with COVID-19. In some cases, these were the first signs to emerge.

Including more than fever, cough, and shortness of breath in symptom-based screening might help catch more cases early in the course of the illness, according to this analysis, which was published in the medical journal JAMA.

Around 18 percent of people with COVID-19 also experience gastrointestinal problems, such as diarrhea or nausea, according to a systematic review published in The European Archives of Oto-Rhino-Laryngology earlier this month. These symptoms are sometimes the first to show up.

In addition to the symptoms mentioned above, the CDC's list of symptoms now includes repeated shaking with chills, headache, sore throat, and new loss of taste or smell. People have also reported loss of appetite and runny noses, and in rare cases, hives or sores on the skin, particularly in children and young adults with suspected COVID-19.

What about seasonal allergies? Along with the viral illnesses that are circulating, it’s also allergy season. Seasonal allergies can cause a mildly scratchy throat; itchy, watery eyes; sneezes; and a runny nose, usually with clear mucus. But if you have a fever or aches or pains, a viral illness is more likely.

When to Seek Testing and Treatment

Most cases of COVID-19 are relatively mild and can be treated at home. (Note: Severe symptoms—which should be considered emergency warning signs—include significant trouble breathing, persistent pain or pressure in the chest, sudden confusion, and bluish lips or face, according to the CDC. See more below, in “You have severe symptoms.”)

As with the flu and the common cold, there is no cure for COVID-19. While certain antiviral drugs, such as oseltamivir (Tamiflu), can sometimes limit the duration and severity of the flu, those drugs have not been shown to help with COVID-19, though at least one antiviral, remdesivir, is being tested, along with other types of potential treatments.

Instead, as it does with the cold and flu, treatment typically focuses on easing symptoms by resting, drinking plenty of fluids, and using over-the-counter pain relievers for fever or accompanying discomfort. 

When to pursue testing or get professional medical care can be more complicated and depends on whether you’re likely to have been exposed, the severity of your symptoms, and your age and underlying health. Here is when to reach out for medical care. 

You have no symptoms, don’t think you’ve been exposed, and are at low risk. People in this group who are younger than 65 and in good health don’t need to get tested, Hochman says. Instead, simply practice basic infection prevention protocols. Wash your hands regularly with soap and water for at least 20 seconds, use an alcohol-based hand sanitizer with at least 60 percent alcohol if you can’t wash your hands, avoid sick people, and listen to recommendations from your local health department.

If you have to go out, wear a cloth face covering to protect others in case you are infected. Everyone should practice social distancing measures, trying to stay home as much as possible and trying to keep at least 6 feet away from others when you do have to go out, according to the CDC. 

You have no symptoms but have had contact with someone who has COVID-19. Currently, the CDC does not recommend that you be tested for COVID-19. But check with your local health department to see whether its guidance differs. Monitor your health carefully and try to avoid public settings—if you can work from home, for instance, do so. It’s especially important to stay alert for symptoms if you are older than 65, are immunocompromised, or have an underlying medical condition such as asthma.

You have mild to moderate symptoms but are at low risk and are unsure whether you’ve been exposed. If you fit into this group and are younger than 65 with no other medical conditions, you can monitor and treat yourself at home, Hochman says. Isolate yourself as much as possible, as you would with the flu. You can consider asking your primary care doctor or health department about testing, but it might not be available, depending on where you live. Call your doctor if symptoms worsen.

You have mild to moderate symptoms and are at high risk. If you’re older than 65 or have underlying health problems, contact your health department or doctor to see about getting tested, even if you are unsure whether you’ve been exposed to the virus. But note that testing may or may not be available.

You have mild to moderate symptoms and know you have been exposed to someone with COVID-19. Contact your doctor or local public health department to see about getting tested, Hochman says. Call first; don’t just show up at a doctor’s office or other healthcare setting, such as a clinic or emergency room, he says—the staff may want you to take special precautions, such as using an alternative entrance and having you wear a face mask upon arrival. Otherwise, you may expose others to the disease or may be exposed yourself by other sick people.

You have severe symptoms. If you have a high fever, a persistent cough that continues to worsen, or shortness of breath that makes it hard to talk, contact a doctor immediately, no matter what your age or risk level. 

And if it feels like a medical emergency, with significant difficulty breathing, call 911, Hochman says. The shortness of breath might make you feel like you have to keep breathing rapidly, as if you just ran a mile, according to Avir Mitra, M.D., an emergency physician at Mount Sinai Hospital in New York City and a spokesperson for the American College of Emergency Physicians. That, more than any other symptom, is a cue that you may need emergency medical attention, he says.

Tell the dispatcher you may have COVID-19 when you call, and put on a cloth mask before emergency personnel arrive.

Editor’s Note: This article, originally published March 12, has been updated to include additional research and expert advice.