What Is Coronavirus (COVID-19)?

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The 2019 novel coronavirus outbreak (COVID-19) is caused by a new type of coronavirus that surfaced in Wuhan, China at the end of 2019. The virus, a member of the family of coronaviruses, is called SARS-CoV-2.

Similar to the coronaviruses that cause Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS), this virus likely jumped from an animal (probably a bat, although scientists are not completely certain) to a human, perhaps via some other species.

The symptoms of COVID-19 appear two to 14 days after exposure. They may include:

  • Fever
  • Cough
  • Trouble breathing
  • Chills
  • Repeated shaking with chills
  • Muscle pain
  • Headache
  • Sore throat
  • Loss of sense of smell or taste

It appears that while the infection is mild in some people, it can cause a severe respiratory (lung) illness similar to SARS and may result in death. It may also cause complications like pneumonia or bronchitis. These complications are more common in babies and the elderly, as well as people with a suppressed immune system or an underlying heart or lung disease.

The World Health Organization has decided COVID-19 is globally widespread enough to be considered a pandemic. This is because the virus is new, so people's immune systems are not prepared to fight it, thus permitting the virus to spread rapidly from person to person.

The interactive map below shows the current extent to which COVID-19 has spread globally. It highlights the total number of confirmed cases and deaths in affected countries, as well as individual states in the U.S.

COVID-19 Transmission

As COVID-19 is still a new virus, understanding its transmission is based on similar coronaviruses. According to the Centers for Disease Control and Prevention (CDC), COVID-19 is thought to spread mainly from person to person. You’re most at risk:

  • If you’re in close contact (within about six feet) with an infected person
  • If you’re exposed to respiratory droplets when an infected person coughs or sneezes

If a person touches a surface or object that has the virus on it, and then touches their own mouth, nose, and possibly eyes, they may contract COVID-19, but the CDC says it’s not the main way the virus spreads.

High-Risk Groups

Based on how COVID-19 affected those in China, it seems the following groups have a higher risk of becoming seriously ill if contracting the virus:

  • Older adults
  • People with lung disease
  • People with asthma
  • People with heart disease
  • People with diabetes
  • People who are immunocompromised (those undergoing cancer treatment, those with immune deficiencies, those with HIV, etc.)
  • People with chronic kidney disease
  • People with liver disease
  • People who are severely obese (BMI of 40 or higher)

People in these groups—or anyone with a chronic medical condition—should take extra precautions to avoid those who are sick, avoid non-essential travel, and avoid crowds. Stay home as much as possible if your area is experiencing community spread, and seek medical attention at the earliest symptoms.


A laboratory test produced by the Centers for Disease Control and Prevention (CDC) is currently being used for COVID-19 testing in the United States, and private companies are earning emergency use authorization from the Food and Drug Administration (FDA) to produce additional tests. This test requires a swab from the patient's nose or throat.

Because of a shortage of tests, a swab test won't be administered on its own. Diagnosis involves obtaining a medical history, including travel history, and a physical examination. Additionally, imaging—including an X-ray or CT scan—may help rule out other causes of illness, or help track disease progression.

If you think you may be sick but haven't received a diagnosis yet, use our printable Doctor Discussion Guide below to help prepare you for talking with your healthcare team.

Coronavirus (COVID-19) Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

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There is not yet a vaccine or specific medicine to treat coronavirus. However, on May 1, 2020, the antiviral remdesivir—initially developed by Gilead Sciences for Ebola—became the first treatment option for COVID-19 to receive emergency use authorization from the FDA.

The FDA has permitted remdesivir to be used in adults and children hospitalized with severe cases of the disease. Treatment for mild coronavirus infections, on the other hand, is supportive, which means doing things to ease your symptoms.

These supportive measures may include:

  • Taking a medication, like Tylenol (acetaminophen), to reduce your fever
  • Using a cool-mist humidifier to help soothe your cough
  • Rest
  • Drinking fluids

A Note on Chloroquine

Chloroquine has been proposed as a possible therapy for the novel coronavirus (SARS-CoV-2) that causes COVID-19. On March 28, 2020, both chloroquine phosphate and hydroxychloroquine sulfate products received emergency use authorization from the FDA for COVID-19. However, this authorization was revoked on June 15, 2020.

On July 1, 2020, the FDA warned of the safety issues leading to this revocation. They include reports of serious heart rhythm problems, as well as kidney, liver, blood, and lymphatic system problems when used to treat COVID-19. They noted that the results of a large, randomized clinical trial showed no benefit for hospitalized patients.

MERS, SARS, and illnesses caused by COVID-19 also require enhanced types of supportive care such as hospitalization, oxygen, fluids, and other life-saving treatment. These may be necessary to support the patient while the immune system responds to and clears the infection.


To prevent the spread of COVID-19, the CDC recommends wearing a mask over your nose and mouth when you are around other people. Besides this, can reduce your risk of contracting human coronavirus by doing what you would do to protect yourself from getting the flu or common cold:

  • Scrub your hands with soap and water for at least 20 seconds (try singing the Happy Birthday song twice for proper timing)
  • Avoid touching your eyes, nose, and mouth
  • Avoid being around people who are sick
  • Using a regular household detergent and water, clean household and work surfaces and objects frequently, especially ones that are touched a lot, such as doorknobs, remote controls, and tables.
How to Properly Wash Your Hands
Verywell / Tim Liedtke

If you are sick, protect others by staying home from work or school. If you live with others, choose and clean a room and bathroom that only you use (if possible).

If you do cough or sneeze, be sure to cover your mouth and nose with a tissue, and then wash your hands after discarding the tissue. Alternatively, if you do not have a tissue available, sneeze or cough into the crook of your elbow.

What Are Coronaviruses?

Coronavirus is a common family of viruses named for its appearance of having a crown (corona in Latin means "crown"). The crown is composed of a protein, called the spike protein, that sticks out from the virus's surface. Here's a look at the SARS-CoV-2 virus that's causing COVID-19:

There are different types of coronaviruses, and while the majority typically cause mild cold symptoms (e.g., runny nose or sore throat), more dangerous types, like the coronaviruses that cause MERS or SARS, may cause more severe disease, including pneumonia, and even death.

Coronaviruses can spread from person to person by the following forms of contact:

  • Droplets: These are produced when someone who has the virus coughs or sneezes.
  • Touch: This includes shaking hands with an infected person or touching an object that contains the virus and then touching your mouth, eyes, or nose prior to washing your hands.
  • Feces: There can be fecal-oral spread from infected patients, but this is believed to be rare.

It is impossible to tell the difference between coronavirus infections and other illnesses based on symptoms alone. While doctors need to take a careful history and perform a physical exam, laboratory tests are needed to accurately diagnose coronavirus infections.

At this time, there are no medicines a person can take to prevent or treat the virus itself. Treatment for coronavirus infections is supportive, which means that the patient is supported while the infection runs its course and the body’s immune system clears the infection.

Types of Coronavirus

Coronaviruses belong to the family Coronaviridae. There are seven types that can infect humans.

Four common types of human coronaviruses cause symptoms of the common cold. These four coronaviruses—229E, NL63, OC43, HKU1—are often referred to as community-acquired coronaviruses because they are common and infect people all over the world.

The other three coronaviruses are more worrisome because they have been linked to severe complications, like pneumonia and death. These three coronaviruses include:

  • 2019 novel coronavirus (COVID-19, originally called 2019-nCOV)
  • Severe acute respiratory syndrome coronavirus (SARS-CoV)
  • Middle East respiratory syndrome (MERS-CoV)
coronavirus types
 Verywell / Gary Ferster


These serious types of coronaviruses jumped from animals to humans, and are potentially life-threatening. According to the CDC, MERS-CoV usually causes fever, cough, and trouble breathing, which often then leads to pneumonia. SARS-CoV causes a similar illness of fever, chills, body aches, and respiratory infection which can be fatal.

There are still cases of MERS, mostly in the Arabian peninsula. There have been no cases of SARS in the world since 2004.

A Word From Verywell

Coronavirus is a common virus that infects people at least once over the course of their lifetime. The good news is that in most cases, it causes a mild, run-of-the-mill "cold." If your symptoms are severe or persistent, or if you have an underlying medical condition, be sure to see your doctor.

The COVID-19 coronavirus is concerning because of the potential for spreading globally, and because it can cause severe symptoms. As more information is gathered on this infection, we hope to remain a resource for you so you can get the information you need.

If you are worried that you may have been exposed to this newly-described virus (e.g., if you are a close contact of someone with COVID-19 or living in a community where person-to-person spread has been reported) and have developed symptoms, please call your doctor promptly for further guidance.

Feelings of fear, anxiety, sadness, and uncertainty are normal during the COVID-19 pandemic. Being proactive about your mental health can help to keep both your mind and body stronger. Learn about the best online therapy options available to you.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. People at risk for serious illness from COVID-19.

  2. Ji W, Wang W, Zhao X, Zai J, Li X. Homologous recombination within the spike glycoprotein of the newly identified coronavirus may boost cross‐species transmission from snake to human. Journal of Medical Virology. 2020; doi:10.1002/jmv.25682

  3. World Health Organization. WHO Director-General's opening remarks at the media briefing on COVID-19.

  4. Centers for Disease Control and Prevention. How COVID-19 spreads.

  5. Food and Drug Administration. Coronavirus (COVID-19) update: FDA issues emergency use authorization for potential COVID-19 treatment.

  6. Centers for Disease Control and Prevention. About coronaviruses: Prevention and treatment.

  7. U.S. Food and Drug Administration. Coronavirus (COVID-19) update: FDA revokes emergency use authorization for chloroquine and hydroxychloroquine.

  8. U.S. Food and Drug Administration. FDA cautions against use of hydroxychloroquine or chloroquine for COVID-19 outside of the hospital setting or a clinical trial due to risk of heart rhythm problems.

  9. Li F. Structure, function, and evolution of coronavirus spike proteins. Annu Rev Virol. 2016;3(1):237-61. doi:10.1146/annurev-virology-110615-042301

  10. Centers for Disease Control and Prevention. Human coronavirus types.

By Colleen Doherty, MD
 Colleen Doherty, MD, is a board-certified internist living with multiple sclerosis.