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What is COVID-19?

COVID-19 stands for COronaVIrus Disease 2019, which is a viral infection. The virus that causes COVID-19 is called SARS-CoV-2. It belongs to the coronavirus family of viruses. Scientists named coronaviruses for the crown-like spikes that stick out from their surface. The Latin word for crown is corona.

Scientists have known about coronaviruses for many decades. There are hundreds of viruses in the family. Most of them circulate among animals, but there are seven coronaviruses that cause disease in humans. SARS-CoV-2 is one of them.

SARS-CoV-2 is a so-called novel coronavirus because it is new to humans. SARS-CoV-2 is a rare example of an animal coronavirus that mutated enough to transition to human hosts. The other two known examples are MERS (Middle East Respiratory Syndrome) and SARS (Severe Acute Respiratory Syndrome). MERS and SARS were more deadly than SARS-CoV-2, but less widespread. The other four coronaviruses cause the common cold and are pervasive throughout the world.

Like other coronaviruses, COVID-19 causes mainly respiratory symptoms in humans. This includes flu-like symptoms, such as fever, cough, body aches, and shortness of breath. However, symptoms vary in severity from mild to severe. Some people with COVID-19 experience a cold-like illness, some feel more like they have the flu, and others have minimal or no symptoms. It generally takes a few days for symptoms to develop after becoming infected.

Anyone can get COVID-19. The disease isn’t likely to be serious in healthy people. In certain people, COVID-19 can cause severe symptoms and is potentially fatal. This includes elderly people and people with underlying medical conditions, such as diabetes, heart disease, and lung disease. In the United States, less than 2% of all reported COVID-19 cases have been fatal.

In most cases, COVID-19 treatment involves treating the symptoms. The kind of treatment you need depends on the severity of the symptoms. Most people recover on their own with home treatments you would use for a cold or flu. This includes resting, drinking fluids, and taking over-the-counter (OTC) medicines. Call your doctor if you are worried about your symptoms or need help finding the right OTC medicine. There are some targeted therapies available under certain circumstances, in particular individuals with mild or moderate COVID-19 who are at high risk for more serious disease.

When symptoms are severe, hospitalization may be necessary. Seek immediate medical care (call 911) for potentially serious symptoms including:

  • Bluish discoloration of the skin, face, lips or nails
  • Chest pain or pressure
  • Confusion
  • High fever
  • Shortness of breath or difficulty breathing

What are the symptoms of COVID-19?

COVID-19 symptoms primarily affect the respiratory tract. They can vary in severity from a mild cold to a flu to serious respiratory distress. Older people and those with poor health are more likely to develop serious symptoms.

Common symptoms of COVID-19

Common symptoms of COVID-19 include:

  • Cough, which is most often dry but can be productive
  • Fatigue
  • Mild shortness of breath

There have also been reports of digestive symptoms, such as diarrhea, and a loss of taste or smell.

Serious symptoms that might indicate a life-threatening condition

In some cases, COVID-19 can be serious and potentially life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have any of these serious symptoms including:

  • Bluish lips, face, nails or skin
  • Extreme sleepiness, difficulty staying awake, or severe fatigue
  • Persistent chest pain or pressure that may worsen with deep breathing or coughing

If you have mild symptoms and think you may have COVID-19, call your doctor. Stay home unless your doctor instructs you to seek medical care. If your symptoms are worsening, seek prompt medical attention.

What causes COVID-19?

The SARS-CoV-2 virus causes COVID-19. SARS-CoV-2 stands for severe acute respiratory syndrome coronavirus 2. It got the name because it is similar to the original SARS-CoV virus that caused a pandemic in 2003. Both viruses belong to the subgroup of beta coronaviruses, along with MERS. Together, these three viruses represent the only known cases where animal coronaviruses made the jump to humans. Because they are new to humans, scientists call them novel—or new—coronaviruses. The other four human coronaviruses cause the common cold and have been around for many decades.

Once SARS-CoV-2 was able to infect humans, it became contagious from person to person. Much like influenza, the virus spreads through respiratory droplets from the nose and mouth. You can inhale these droplets when an infected person sneezes, coughs, or forcefully exhales near you. The droplets can also contaminate surfaces where you can pick them up on your hands. According to the CDC (Centers for Disease Control and Prevention), respiratory transmission is much more common than surface transmission. The virus can also spread in smaller droplets and aerosols that linger in the air longer than larger droplets.

What are the risk factors for COVID-19?

Anyone who comes in contact with other people is at risk of contracting COVID-19. Most people will not develop serious disease. However, there are factors that increase the risk of developing severe disease. Not all people with risk factors will have problems. Risk factors include:

  • Advanced age. Risk of severe disease increases with age (for example, people who are 60 are at higher risk than people who are 40); older adults (85 years or older) are at greatest risk.
  • Taking immunosuppressant medications or having a weakened immune system due to cancer, HIV, or other conditions

Reducing your risk of COVID-19

Basic personal hygiene is the key to COVID-19 prevention. You may be able to lower your risk of COVID-19 by:

  • Frequently cleaning high-touch objects and surfaces with cleaners that will kill bacteria and viruses
  • Covering your nose and mouth with a tissue when you cough or sneeze. Be sure to safely dispose of it immediately. You can use the corner of your elbow if you don’t have a tissue available.
  • Keeping at least six feet away from someone who is visibly sick. This is the basis of current social distancing guidelines.
  • Not touching your eyes, nose or mouth
  • Staying home if you have potential COVID-19 symptoms or don’t feel well
  • Washing your hands with warm, soapy water for 20 seconds at a time. Do this several times a day, especially before eating or touching your face. You can use an alcohol-based hand sanitizer if soap and water are not available.
  • Avoid indoor public gatherings, especially spaces with poor ventilation.
  • Getting the COVID-19 vaccine, which is authorized for everyone ages 12 and older (depending on the manufacturer).

Current CDC recommendations to slow the spread of COVID-19 include (in addition to vaccination) wearing a mask or other face covering. In infection control, masks and face coverings are a form of source control. This means their role is to protect others around you should you be infected with the virus. They do this by providing a barrier to respiratory droplets.

Medical masks and cloth face coverings can also protect the wearer because the mask can filter out small particles. The degree of filtration depends on the electrostatic properties of the mask and the number of layers of fabric. For example, a three-ply cotton mask is a better "filter" than a bandana folded in half.

If you are fully vaccinated against COVID-19 you do not need to wear a mask or physically distance in any setting, unless required by local officials, businesses or workplaces.

How is COVID-19 treated?

The U.S. Food and Drug Administration authorized special use of two new therapies for people with mild-to-moderate COVID-19 disease at high risk for developing more severe disease. They are monoclonal antibodies that target the SARS-CoV-2 spike protein. They have been shown in clinical trials to reduce emergency room visits and hospitalizations.

For people with mild-to-moderate COVID-19 who do not meet the FDA's eligibility, treatment involves relieving symptoms and preventing complications. Most people are able to treat COVID-19 and recover safely with home treatments including:

  • Resting as much as possible
  • Staying home while you have symptoms
  • Taking OTC medicines as needed to help control cough, bring down a fever, and relieve other symptoms
  • Using a humidifier or inhaling the steam from a hot shower to loosen and relieve a cough

If you need help choosing an OTC medicine for your symptoms, talk with your doctor or pharmacist. Your medical history can play a role in the safety and suitability of OTC cold and flu medicines. Discuss any chronic conditions with your healthcare provider.

When COVID-19 is severe, hospital care may be necessary. Hospital staff will monitor for complications while providing supportive treatments. This may include IV (intravenous fluids), powerful anti-inflammatory corticosteroids, biologic drugs, and supplemental oxygen.

Scientists are currently studying potential antiviral medicines for COVID-19. This includes the drug remdesivir, which was granted emergency use authorization in May. In October, the FDA (Food and Drug Administration) granted approval for remdesivir for patients 12 and older hospitalized for COVID-19 because it has been shown to be both safe and effective for improving COVID-19 symptoms and shortening recovery time.

The FDA also authorized emergency use of convalescent plasma therapy. This approach uses donor plasma from someone who has already recovered from COVID-19. Plasma contains antibodies, which are proteins the immune system makes to fight germs. Early in the pandemic, doctors found that infusing these antibodies from a donor helped some hospitalized patients fighting the infection recover more quickly and easily. However, data from other clinical trials show that the effect in people with mild or moderate COVID-19 is not significant. There is also minimal effect in hospitalized patients. Patients can still receive convalescent plasma through its emergency use authorization.

What are the potential complications of COVID-19?

Most people who get COVID-19 will have a mild or moderate infection. However, it is possible to have severe disease with serious symptoms. Those at highest risk of complications include the elderly and those with underlying medical conditions.

In high-risk groups, COVID-19 can cause critical disease with serious and potentially fatal respiratory distress. If you belong to a high-risk group, talk with your doctor about ways to protect yourself from COVID-19 infection. Find out what to do if you develop symptoms and know when to seek emergency medical care.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Sep 10
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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