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.
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
According to the Centers for Disease Control and Prevention (CDC), the disease may cause:
- a fever, chills or both
- a cough
- difficulty breathing
- a headache
- muscle aches
- a new loss of taste or smell
- a sore throat
- nasal congestion or a runny nose
- nausea or vomiting
According to the WHO,
Older adults and people with certain medical conditions appear to have a
The risk of severe illness from COVID-19 increases as a person gets older. The greatest risk is among people aged
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
- type 2 diabetes
- obesity, classed as a body mass index (BMI) of 30 or above
- chronic kidney disease
- chronic obstructive pulmonary disease, known as COPD
- heart disease
- a weakened immune system due to a solid organ transplant
- sickle cell disease
- Down syndrome
Down syndrome is not a health condition. However, some people with Down syndrome have specific health factors that increase their risk.
The following factors may also have an impact:
- overweight, classed as a BMI of 25–29.9
- high blood pressure
- moderate to severe asthma
- a weakened immune system due to a blood or bone marrow transplant, immune deficiencies, HIV, the use of corticosteroids, or the use of other immune-weakening medicines
- dementia or other neurologic conditions
- liver disease
- pulmonary fibrosis, which damages lung tissue
- type 1 diabetes
- cerebrovascular disease, which affects the blood vessels and blood supply to the brain
- cystic fibrosis
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.
Social and race inequity
Compared with white people, Black and Hispanic people have
- 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.
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.
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.
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 testif 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
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.
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.
Seek immediate medical attention for:
- difficulty breathing
- persistent pain or pressure in the chest
- an inability to stay awake
- a bluish tinge to the lips or face
Research into detailed outlooks for groups with COVID-19 is ongoing.
The duration of COVID-19 symptoms varies widely. People often feel better within 2 weeks, but for some, this takes much longer.
Some people have
- difficulty breathing
- a cough
- chest pain
- joint pain
People have also reported:
- difficulty focusing
- muscle pain
- a fever that comes and goes
- heart palpitations
problems with taste and smell
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.
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
There is also
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.
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.
Meanwhile, continue with physical distancing, frequent hand washing, avoiding touching the face, and wearing a face-covering in public.