FYI: It can look a lot like the flu.

By Leah Groth
Updated July 14, 2020

Since it was first reported in Wuhan, China, in December 2019, the novel coronavirus (COVID-19) has become a global health issue. As of July 14, it has sickened more than 13 million people and claimed the lives of more than 570,000 worldwide, reports the World Health Organization (WHO).

While different parts the US are experiencing different levels of COVID-19 infection, no state is immune. New cases are currently on the rise in 40 states, with serious outbreaks in Florida, California, and Texas, among others.

Public health officials now recognize that people may spread the disease before they become symptomatic. Newly revised estimates from the Centers for Disease Control and Prevention (CDC) suggest that 40% of folks don't have symptoms, and half of all new cases are transmitted by infected person before they develop symptoms. 

If you do happen to feel something coming on, how do you know whether it's COVID-19? Here are the core symptoms to watch out for and how it differs from other illnesses.

What are the symptoms of coronavirus?

First of all, coronaviruses are a group of different viruses—and the symptoms of the current newsworthy strain of coronavirus, COVID-19, differ from other coronavirus strains.

Three symptoms—fever, cough, and shortness of breath—were initially recognized as core signs of COVID-19, but it has become increasingly clear that the signs and symptoms of this illness can be quite diverse. The CDC has revised and expanded the list of symptoms more than once. Fever or chills, cough, and shortness of breath or difficulty breathing are still possible indicators. Other signs include: fatigue; muscle or body aches; headache; new loss of taste or smell; sore throat; congestion or runny nose; nausea or vomiting; and diarrhea. 

The signs and symptoms of COVID-19 look a lot like the flu. Common flu symptoms include fever, cough, sore throat, muscle aches, and headache, says the CDC.

Fever, cough, and shortness of breath are more common in people hospitalized with COVID-19 than individuals with milder cases of illness, according to updated CDC guidance. Complaints of fatigue, headache, and muscle pain are more common among people with milder illness, who don't require hospitalization. Symptoms like sore throat and runny nose or nasal congestion may also be present with milder disease.

Symptoms of the Delta variant, which originated in India, are slightly different than those of the first variant that spread through the US. "COVID is acting differently now. It's more like a bad cold; people might think they've just got some sort of seasonal cold," Tim Spector, professor of epidemiology at King's College London, explains in a video released on YouTube by the COVID Symptom Study. He explains that the number one top symptom for those with the Delta variant is headache, and this is followed by sore throat, runny nose, and fever. "Those are not the old, classic symptoms," Spector says. "Number five is cough, [though] it's rarer." He adds that loss of smell isn't among the top 10 reported symptoms for those with the Delta variant.

How does coronavirus progress?

The CDC explains that symptoms appear to arise in as few as 2 days after exposure to the virus or as long as 14 days. According to an analysis in the Annals of Internal Medicine, this estimated time frame is similar to the incubation period of SARS and MERS, which are also types of coronaviruses.

However, the progression of COVID-19 varies widely. Initially, some people have very mild symptoms, like headache or low-grade fever, while others experience no symptoms at all. Among people who develop severe disease, the CDC warns healthcare providers of "the potential for some patients to rapidly deteriorate one week after illness onset."

If you think you've been exposed to COVID-19 or are experiencing fever or other symptoms, such as cough or difficulty breathing, call your healthcare provider, the CDC suggests. Anyone who is having trouble breathing or experiencing other concerning symptoms, like chest pain, confusion, or bluish lips or face, ought to seek immediate medical care.

How can you protect yourself from coronavirus?

The WHO suggests a variety of safety measures to take to keep yourself safe from the novel coronavirus, which include hand and respiratory hygiene.

First and foremost, it's advised that people frequently clean their hands with soap and water or by using alcohol-based hand gel. It's also important that, when coughing and sneezing, people always cover their mouth and nose with their elbow or a tissue (and then immediately throw that used tissue away and wash their hands). People should also try their best to avoid others who have a fever or cough.

Avoid touching your eyes, nose, and mouth, because if the virus is on your hands, it can enter your body through your mucus membranes and make yourself sick, says WHO.

It's also important to maintain "social distancing"—leaving a buffer zone of about 6 feet between people to prevent person-to-person transmission, the CDC recommends. It also says everyone should wear a cloth face covering when in public or around people not in your household, especially when you cannot maintain physical distancing.

Clean and disinfect any surfaces your touch daily, the CDC adds. And, by all means, if you are sick, stay home and recover. If you develop serious symptoms, call your healthcare provider.

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDC, WHO, and their local public health department as resources.

To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter