Patient information from BMJ

COVID-19 (coronavirus)

Last published:Jun 13, 2023

This leaflet is about the COVID-19 (coronavirus) outbreak that began in China in late 2019. The World Health Organization (WHO) has declared the outbreak a pandemic. This means that it has spread across the world. In May 2023, the WHO declared that while the pandemic is not over, the public health emergency that it caused has ended for now.

This virus can cause a severe lung infection, and it can cause death. You can use our information to talk with your doctor if you are concerned about COVID-19.

What is COVID-19?

COVID-19 is a disease caused by a type of virus called a coronavirus. This is a common type of virus that affects both animals and humans. Coronaviruses often cause symptoms like those of the common cold. But sometimes they can cause more serious infections.

The coronavirus that causes COVID-19 is a new type of coronavirus. Most of the first people affected had links to a seafood and live animal market in Wuhan City, Hubei Province, China. This suggests that this new coronavirus might be a combination of human and animal coronaviruses.

The virus has spread around the world, with cases recorded in all continents.

How do people catch COVID-19?

COVID-19 is able to spread from person to person, usually through the air. The virus spreads most easily when people cough or sneeze, particularly when they are close together indoors.

Infected people can spread this virus even if they don't have any symptoms yet.

You are more likely to get the infection if:

  • you have been in close contact with someone who has COVID-19

  • you are older

  • you are male

  • you are obese (very overweight)

  • you live or work in a location with a high risk of transmission

  • you are having treatment for cancer

  • you may also be more likely to get the infection if you have other chronic illnesses.

Research in some countries, including the US, has found that people of black and Asian origin are more likely than white people to become infected and to have severe symptoms.

What are the symptoms?

It's thought that people can have the virus for up to 14 days without having any symptoms. This time before symptoms develop is called the incubation period. The average incubation period is 5 to 7 days.

Some people who get COVID-19 don't get any symptoms at all. But many will have an illness like a cold or flu. Some people will have a more severe illness, like pneumonia.

You’re more likely to have a severe illness if:

  • you are older

  • you live in a nursing home or care home

  • you are male

  • you are obese

  • you are a current or former smoker

  • you have diabetes

  • you have cardiovascular disease (a condition affecting your heart or your blood vessels: for example, heart attack, stroke, heart failure, angina)

  • you have a long-lasting condition that affects your lungs, such as asthma or chronic obstructive pulmonary disease (COPD) or cystic fibrosis

  • you have chronic kidney disease

  • you have chronic liver disease

  • you have cancer

  • you are pregnant

  • you have had a stroke

  • you have a mental health condition, such as depression or schizophrenia

  • you have a disability, such as cerebral palsy or Down syndrome

  • you have a weakened immune system

  • you have dementia

  • you have had an organ or stem cell transplant

  • you are recovering from surgery.

The most common symptoms of COVID-19 are:

  • fever

  • coughing

  • shortness of breath

  • loss of sense of smell, and

  • reduced sense of taste

Less common symptoms can include:

  • aches and pains

  • feeling tired

  • sore throat

  • headache

  • blocked or runny nose

  • sneezing

  • coughing up a lot of phlegm

  • diarrhea

  • feeling nauseous or vomiting

  • abdominal (tummy) pain

  • loss of appetite

  • confusion

  • dizziness

  • conjunctivitis (red or watery eyes) or dry eyes

  • pain or tightness in the chest

  • skin rashes

  • chilblains, and

  • coughing up blood.

Children seem to be less severely affected than adults. But there have been reports of COVID-19 causing a severe illness in children, with fever, rash, heart and stomach problems, and other complications.

This is very rare. But if you have concerns about your child, it’s very important to speak to a doctor as soon as possible.

As you can see, many of the less serious symptoms of COVID-19 are similar to those of a cold or flu. So it can be hard to diagnose COVID-19 without testing, but tests are available.

If your doctor thinks that you might have severe COVID-19, you might need some tests, such as blood tests, a chest x-ray, or another type of scan of your chest called a CT (computed tomography) scan.

Some people who are seriously ill with COVID-19 can develop problems with their kidneys, liver, blood, heart, or brain. If this happens, you might need more tests and extra care.

Pregnant and breastfeeding women

We don't know for certain whether the virus can pass from a mother who is infected to her baby in the womb, or to a baby through breastfeeding, but there have been cases reported. The risk of becoming seriously ill from COVID-19 is higher in pregnant women, especially in later pregnancy.

The symptoms of COVID-19 during pregnancy are the same as in people who are not pregnant.

If you are pregnant and you develop symptoms, you should contact your doctor right away. You might need regular ultrasound scans during your pregnancy if you have had COVID-19. And you and your baby might need extra monitoring during labour and after the birth.


You can take measures to reduce your risk of being infected with COVID-19. These include:

  • getting vaccinated - different vaccines are available to protect people against COVID-19 and booster programs are continuing in many countries, especially for people with an increased chance of having severe symptoms if they are infected

  • washing your hands often with soap and water, especially after being in a public place. If soap and water are not available, use an alcohol-based hand sanitizer containing at least 60 percent alcohol

  • avoiding touching your eyes, nose, and mouth with unwashed hands

  • cleaning and disinfecting frequently touched surfaces every day, including counter tops, phones, light switches, handles, and door knobs

  • wear a mask in spaces that are closed, crowded, or involve close contact

  • avoid close contact with people, especially those who are sick. It is recommended that people stay at least 1 to 2 meters away from others, but the recommended distance between people varies between countries.

If you choose to wear a mask, you should wash your hands with soap and water, or use an alcohol-based hand sanitiser, before putting on the mask. You will still need to wash your hands often and thoroughly while wearing the mask.

You should follow any national or regional policies on social distancing. These policies can change quite quickly, depending on the spread of a particular variant of the virus, and on how local health services are affected.

If you become ill, you should:

  • stay home and avoid contact with other people

  • seek medical care right away if you need it. But call ahead to your doctor or emergency department and tell them about your symptoms

  • contact your doctor or health care provider if you have been identified as being at the highest risk from COVID-19, as you may be eligible for treatment

  • not travel while you are unwell

  • cover your mouth and nose with a tissue or your sleeve (not your hands) when coughing or sneezing, then put the tissue into the bin

  • wash your hands often with soap and water, especially after coughing, sneezing, blowing your nose, or being in a public place. If soap and water are not available, use an alcohol-based hand sanitizer containing at least 60 percent alcohol.

What treatments are available?

There is no cure for COVID-19.

A type of drug called an antiviral, which means that it is used to fight viruses, can be given to patients who have or are at risk of progression to severe COVID-19.

Other drugs called monoclonal antibodies are also being used to treat people who are thought to be at risk of having severe COVID-19 infection. These drugs can reduce someone's chances of having severe symptoms or of dying, depending on the variant of COVID-19 that is circulating.

Other drugs are being studied to see if they might be useful. And there are many more treatments available than at the start of the pandemic.

Hospital treatment

If you are treated in the hospital, the treatment might consist of:

  • rest

  • making sure you get plenty of fluids, possibly through an IV (intravenous) drip

  • medication to lower fever and reduce pain and help with other symptoms, if needed

  • oxygen, if you need it

  • medication to prevent blood clots

  • steroids

  • antiviral medication

  • medication to help decrease inflammation in the body, and

  • close monitoring.

You might also be given antibiotics to begin with, in case you have a bacterial infection. But if testing shows that you have a viral infection, the antibiotics will be stopped, as antibiotics don’t work against viruses.

People with severe symptoms might be treated in an intensive care unit (ICU). If you need to be treated in intensive care, your treatment might also include:

  • a tube passed through your mouth to your windpipe, called an endotracheal tube, and

  • a ventilator to support your breathing.

Some people being treated in the hospital might also need treatment for sepsis or other complications.

Home treatment

People who are seriously ill will probably be isolated and treated in the hospital.

But if someone has mild symptoms of suspected COVID-19, they can probably be looked after at home.

The guidance for looking after them at home is as follows:

  • They should be looked after in a well ventilated room by themselves, and should stay in that room as much as possible, so that they don’t spread the infection.

  • The number of people who look after the ill person should be limited to as few as possible.

  • Ideally, anyone looking after the ill person should be in good health.

  • If you wear a medical mask while looking after someone with symptoms, change it for a new one if it comes into contact with their bodily fluids.

  • Wash your hands thoroughly after touching the ill person. You might want to wear disposable gloves, such as latex gloves.

  • Dispose carefully of any tissues the person uses.

  • Don’t share anything like towels or bedclothes with the ill person.

  • Carefully wash any plates, drinking glasses and silverware after they use it.

  • Regularly wipe and disinfect any surfaces the person touches regularly, such as bedside tables.

  • Clean toilet and bathroom surfaces regularly.

  • Clean all clothes, bedclothes, and towels used by the ill person at 140° F.

  • Keep taking any prescribed medications, unless your doctor recommends that you stop.

Recovery and long-lasting symptoms

Most people recover quickly from COVID-19. But some people will have symptoms that last for weeks. And some people’s symptoms will last for months. You might have heard the term “long covid” used to describe symptoms that go on for a long time (usually more than 3 months).

These long-lasting symptoms are more likely to happen if your symptoms were severe to begin with. But they can happen to people of any age who have had the coronavirus. These symptoms can come and go, so that you have good and bad days.

The most common ongoing symptoms seem to be:

  • coughing

  • low-grade fever, and

  • fatigue.

Other, less common ongoing symptoms can include:

  • shortness of breath

  • pain, including chest pain, headaches, or just general aches and pains

  • rashes

  • upset stomach

  • problems with memory and concentration, and

  • mental health problems, such as posttraumatic stress disorder (PTSD).

Many other symptoms have been described.

If you have severe ongoing symptoms, your doctor might suggest tests, such as blood and urine tests to look for infections, or x-rays.

It might be that these symptoms will ease or disappear given time and rest. But we don't know enough about covid yet to be sure what is likely to happen.

If you have been treated in the hospital for severe COVID-19, your doctor should arrange for any ongoing treatment that you need. But even if you didn’t need hospital treatment, you can still have long-lasting symptoms. Talk to your doctor about what help might be available.

Mental health issues affect many people who have suffered with COVID-19. For example, many people struggle with stress, anxiety, and PTSD. If you feel that you need help, talk to your doctor, and to family and friends.

What to expect in the future

It’s not possible to say what will happen to someone infected with COVID-19. The outcome can vary. What we know is that:

  • the infection is most likely to be serious in older people with existing long-term health problems. But most people with COVID-19 don't become seriously ill

  • more than 760 million confirmed cases have been reported worldwide

  • almost 7 million people have died.

The best thing you can do is to get vaccinated, particularly if you’re at higher risk of infection or serious illness. Follow any other prevention measures that are in place and know what to do if you feel ill. This will help to protect you and the people around you.

If you usually do a lot of exercise, you should rest for at least two weeks after recovering from COVID-19 or testing positive for coronavirus. You should speak with your doctor about when you can start exercising again.

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