COVID-19 is a highly contagious disease that results from an infection with the virus SARS-CoV-2, a type of coronavirus.

COVID-19 can occur without any symptoms. It can also cause symptoms that are severe and complications that can be fatal. Doctors do not yet know the full impact that it has on the body, but COVID-19 commonly affects a person’s ability to breathe.

Even if a person has no symptoms, they can pass the infection to others. It is vital to take steps to prevent this.

There is no cure for COVID-19. To prevent the illness, take precautions, such as washing the hands frequently, wearing a face-covering in public, and staying away from others. Isolating is especially crucial for people who feel ill.

Vaccines are becoming available and are free for everyone in the United States. Learn about vaccine options in the U.S. and elsewhere.

This article looks at the symptoms of COVID-19 and how the underlying infection spreads. We also explain what to expect and what to do if symptoms arise.

For more advice on COVID-19 prevention and treatment, visit our coronavirus hub.

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A person can still transmit SARS-CoV-2 even if they do not have symptoms.
Image credit: Joe Raedle/Getty Images

COVID-19 results from an infection with a coronavirus, SARS-CoV-2. Coronaviruses are a large family of viruses that can cause respiratory illnesses. These range from the common cold to severe acute respiratory syndrome (SARS).

The symptoms of COVID-19 may begin 2–14 days after exposure to the virus, and they can vary widely. A person may have no symptoms, or the symptoms may range from mild to severe. In some cases, COVID-19 is fatal.

According to the Centers for Disease Control and Prevention (CDC), the disease may cause:

The World Health Organization (WHO) list the following less common symptoms:

According to the WHO, about 80% of people with COVID-19 recover without needing hospital treatment. Around 20% become seriously ill and about 5% need intensive care.

Older adults and people with certain medical conditions appear to have a higher risk of developing severe COVID-19.

COVID-19 can also affect young people, including those with no known health conditions.

Older adults

The risk of severe illness from COVID-19 increases as a person gets older. The greatest risk is among people aged 85 years and above.

In the U.S., around 8 in 10 deaths from COVID-19 have been among people aged 65 or older.

Individuals in this age group should take very careful precautions to avoid contact with the virus. This might involve asking a neighbor or family member to collect groceries, for example.

People with preexisting health conditions

Doctors continue to identify factors that may increase the risk of becoming severely ill with COVID-19.

Below are some factors that are likely to have this effect, according to the CDC:

Down syndrome is not a health condition. However, some people with Down syndrome have specific health factors that increase their risk.

How does COVID-19 affect people with diabetes?

The following factors may also have an impact:

Anyone with an underlying health condition should continue to attend healthcare appointments, take care to avoid exposure to the virus, and seek medical advice if they may have symptoms.

What to do about COVID-19 if you have asthma.

Learn more about how SARS-CoV-2 affects the body.

Social and race inequity

Compared with white people, Black and Hispanic people have higher risks of having COVID-19 and developing severe symptoms, due to factors such as:

  • lower access to quality healthcare, increasing the risk of underlying conditions
  • discrimination in healthcare and other social systems
  • wealth and income gaps
  • a higher likelihood of contact with others or the virus at work
  • overcrowded housing and other housing issues

The issues above are true for younger people, as well as for older adults.

What is health equity, and why is it crucial? See our dedicated hub to learn more.

The CDC urge people to take additional care to avoid the infection that causes COVID-19 during pregnancy. Pregnant people may be more likely to develop severe symptoms, and there may be a higher risk of preterm birth.

The risk of the virus passing to a baby during pregnancy or delivery appears to be low, though some newborns have tested positive soon after delivery. In most cases, the infants had mild or no symptoms, but some have had more severe illness.

Anyone who has COVID-19 around the time of delivery should ask their healthcare provider for specific advice about the delivery and caring for the newborn.

Continue attending regular appointments, and raise any concerns with the healthcare team. Ask about any extra precautions that may be necessary.

Learn more about pregnancy and COVID-19 here.

SARS-CoV-2 appears to spread primarily through close person-to-person contact. It can transmit from a person even if they have no symptoms.

When someone with the virus talks, coughs, or sneezes, tiny droplets containing the virus spray from their nose or mouth into the air. The virus can then pass to anyone nearby.

A person can also develop the infection after touching a surface where the virus is present, then touching their face — especially their nose, mouth, or eyes.

The longer a person spends with someone who has the virus, and the closer they are, the higher the risk of transmission, especially indoors.

There is some evidence that droplets containing the virus may remain in the air for some time after the person with the virus has moved on.

Research also suggests that the virus can last for up to 24 hours on cardboard and up to 72 hours on plastic and stainless steel surfaces.

Current guidelines recommend staying at least 6 feet away from others. But new strains of the virus appear to spread more easily, indicating that a farther distance may be necessary.

Overall, the more precautions a person takes, the better their chances of avoiding the infection and limiting the spread of COVID-19.

Learn more about how coronavirus spreads here.

A person can protect themselves and prevent the spread of COVID-19 by following these guidelines:

  • Wash the hands often with soap and water for at least 20 seconds at a time.
  • When soap and water are unavailable, use a hand sanitizer with a high alcohol content frequently.
  • Avoid touching the face, eyes, nose, and mouth.
  • Maintain a distance of at least 6 feet (2 meters) from others.
  • Cover coughs and sneezes with a tissue or the inner elbow. Dispose of the tissue immediately. Wash the hands.
  • Frequently clean and disinfect surfaces such as tabletops, counters, doorknobs, and handles.
  • Avoid sharing personal items, such as cups and towels.
  • Use a face-covering in public and anywhere where it is difficult to stay 6 feet away from others.
  • Have a test if symptoms appear, and take appropriate precautions if the result is positive.
  • Get vaccinated as soon as the vaccine becomes available.

Health authorities, including the CDC, provide instructions for making a mask at home.

Face-coverings can help stop the virus from spreading through droplets in the air. They can also reduce the risk of the virus entering the body if a person touches their face after contact with a contaminated surface.

Find more tips on prevention here.

Anyone with symptoms that may indicate COVID-19 should:

  • Stay home, unless a doctor advises otherwise.
  • Have a test to show whether the virus is present.
  • Stay away from others at home as much as possible.
  • Seek medical care if breathing difficulties occur.
  • Call ahead before visiting a doctor’s office or urgent care center, letting the staff know that COVID-19 is a possibility.

There is no cure for COVID-19, but treatments can help relieve the symptoms.

At home, a person should:

  • Get plenty of rest.
  • Drink plenty of fluids.
  • Have small, but frequent, nutritious meals.
  • Take acetaminophen (Tylenol) to ease any pain and reduce a fever.

Learn more about possible treatments for COVID-19.

Seek immediate medical attention for:

  • difficulty breathing
  • persistent pain or pressure in the chest
  • confusion
  • an inability to stay awake
  • a bluish tinge to the lips or face

Research into detailed outlooks for groups with COVID-19 is ongoing.

Recovery time

The duration of COVID-19 symptoms varies widely. People often feel better within 2 weeks, but for some, this takes much longer.

The CDC recommend isolating at home for 10 days following the appearance of symptoms and for at least 24 hours after any fever ends. Upon release from a hospital, a person may need to isolate for an additional 10 days.

‘Long COVID’

Some people have long-term effects of COVID-19, regardless of how severe their original symptoms were.

These include:

  • fatigue
  • difficulty breathing
  • a cough
  • chest pain
  • joint pain

People have also reported:

There is also concern about possible long-term cardiovascular and neurological problems, as well as those affecting other body systems.

It is still unclear how long these symptoms are likely to remain.

Here, learn more about the long-term effects of COVID-19.

Fatality rates

Current figures suggest that COVID-19 is fatal in 1.7% of cases in the U.S.

Fatality rates vary among countries due to factors such as testing policies, relative populations of older people, and available healthcare staff and facilities.

A changing picture

New variants of the virus are now appearing, making the course of the infection less predictable. Some variants appear to spread more easily, but there is currently no evidence that any cause more severe illness.

There is also evidence that the virus started infecting increasingly more young people a few months after the pandemic began. However, this may indicate a change in the pattern of exposure rather than a change in the virus.

Reinfection

Someone who has had the infection may have immunity for “several months” afterward, according to a report published on the preprint server medRxiv in January 2021.

The study of more than 20,000 healthcare workers in the United Kingdom found that those who had already developed COVID-19 had an 83% lower risk of developing it again within 5 months.

During this time, the virus may still be present in the body and able to transmit to others.

For up-to-date news and statistics, see our COVID-19 live updates page.

COVID-19 is a highly contagious respiratory disease caused by the virus SARS-CoV-2.

Many people experience mild illness, but some develop severe and sometimes life-threatening symptoms. A person with COVID-19 may have no symptoms, but in this case, the virus can still pass on to others.

There is currently no cure for COVID-19, but treatments can help relieve the symptoms and support breathing. Some people require hospital care.

Vaccines are starting to become available. Here, learn more about vaccines that offer protection from COVID-19.

Meanwhile, continue with physical distancing, frequent hand washing, avoiding touching the face, and wearing a face-covering in public.