What is coronavirus (COVID-19)?
Coronavirus (COVID-19) is a respiratory illness that affects the airways and lungs. It was first seen in humans in 2019, and is caused by SARS-CoV-2 – a type of coronavirus.
Coronaviruses are a large family of viruses that can infect humans and animals. Some cause mild respiratory infections, like the common cold, while others cause more severe illnesses, such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS).
What are the symptoms of COVID-19?
It’s thought that around 1 in 3 people who have COVID-19 don’t show any symptoms.
But if you do develop symptoms, you’re most likely to have 1 or more of the following:
- cough – usually new and ongoing (coughing a lot for at least an hour or having more than 4 coughing episodes every day). If you already have a cough, it may feel worse than normal
- trouble breathing
- a change in your sense of smell or taste
- feeling tired and weak
You may also notice some less common symptoms, like:
- aches and pains
- blocked or runny nose
- sore throat
- feeling sick (nausea) or being sick (vomiting)
These symptoms usually begin 4 to 5 days after you’ve been infected, but they can appear anytime between 2 days and 2 weeks after infection.
Most people who develop COVID-19 get better within a few weeks, but for some, the symptoms continue for weeks or months – a condition known as long COVID-19 (or long COVID).
Anyone who has had COVID-19 can go on to develop long COVID-19 – even if they had mild symptoms or no symptoms at all. But it’s still not clear why some people get it and others don’t.
What is severe COVID-19?
While most people who get COVID-19 develop a mild version, which features some or all of the symptoms listed above, a small number develop a serious form, called severe COVID-19.
Severe COVID-19 causes a really bad infection that leads to complications like pneumonia, extreme shortness of breath, and heart, kidney and brain failure. These complications can lead to death, especially in people aged over 50.
Your risk of getting severe COVID-19 typically depends on how old and how healthy you are. In general, it’s more likely the older you are, if you smoke and if you have other health conditions, like:
Read more about severe COVID-19 and how it differs from mild COVID-19.
When to see a doctor about COVID-19?
COVID-19 can be life-threatening in some cases, so get medical help if you have:
- difficulty breathing
- a fever
- a new, continuous cough
- any other symptoms of COVID-19 listed above
But don’t go to your doctor’s office or the emergency room. Instead, call your country's dedicated coronavirus helpline. They will usually ask you about your symptoms, who you’ve been in contact with and if you’ve travelled recently, before deciding if you need to take a test or see a doctor in person.
If they suggest that you don’t need to see a doctor or go to a testing clinic, stay indoors and avoid close contact with other people until you feel better and you’ve had a negative test result.
If it's an emergency, call an ambulance and tell them your symptoms so the paramedics and hospital staff can take measures to reduce the risk of infecting others.
How is COVID-19 spread?
COVID-19 is most commonly spread between people through tiny droplets that an infected person releases into the air when they cough, sneeze or talk.
It can also be passed on by touching your face after handling objects and surfaces an infected person has also touched.
Being in close contact with an infected person increases your chances of catching the virus – whether they have symptoms or not. That’s why governments and health authorities recommend social or physical distancing – staying at least 2 metres away from people you don’t live with. But, this recommendation was made during a COVID-19 outbreak and may change over time.
Other things you can do to reduce your risk of catching or spreading the virus include:
- covering your mouth and nose with a tissue or your sleeve when coughing or sneezing
- washing your hands regularly with warm water and soap – wash for at least 20 seconds and wash them as soon as you get home
- throwing used tissues away immediately
- using an alcohol-based hand sanitiser if soap and water are not available
- avoiding close contact with people who are unwell
- not touching your eyes, nose or mouth if your hands are not clean
- allowing fresh air into your home often
- wearing a face covering when you’re around other people – read more about the best face masks for COVID-19
How is COVID-19 diagnosed?
Guidelines for getting tested vary from country to country, but if you have symptoms of COVID-19 or have been in contact with someone with the illness, you may be able to get a test (known as a PCR swab test) to see if you have the virus. During this test, the inside of your nose and throat will usually be swabbed with a long cotton bud.
There’s also another test to check if you've had COVID-19. This involves having a blood test known as an antibody test.
But keep in mind that no test is 100% accurate, so there’s a small chance that you could have COVID-19, even if you have a negative test.
General guidance suggests there’s no need to self-isolate (stay at home) unless you have or might have COVID-19.
You should self-isolate for up to 14 days if:
- you or someone you live with have COVID-19 symptoms
- you or someone you live with have had a positive COVID-19 test
- someone you’ve been in close contact with has COVID-19 symptoms or has tested positive for the condition
- a contact tracing service tells you you’ve been in contact with someone with COVID-19
But, always check local guidelines for information specific to your city or country. During an outbreak, different regions may use different rules to limit the spread of infection.
How is COVID-19 treated?
If you don’t have severe COVID-19, you can usually manage your symptoms at home, using self-care measures like:
- getting lots of rest
- opening a window to cool your room – if you’re feeling breathless
- taking simple painkillers if you’re in pain
- drinking lots of water to stay well hydrated
- taking a teaspoon of honey or using cough syrups or lozenges to soothe a cough – call a pharmacist (or use an online pharmacist service) for advice on the best thing to take for a cough and use it as directed
- sitting upright, leaning forward and slowly breathing in through your nose and out through your mouth – if you feel breathless
Most mild cases of COVID-19 get better on their own within 2 weeks – although this can take longer in some cases or if you have long COVID-19.
Remember that you’ll need to self-isolate for up to 14 days (or until a health professional tells you to stop self-isolating) if you have COVID-19.
If you have more serious symptoms that suggest you may have severe COVID-19, you may need to be treated in hospital.
This treatment won’t cure the infection itself – there’s currently no treatment to kill the virus that causes COVID-19 – but it will typically help to manage the symptoms and complications.
Treatments for severe COVID-19 may include:
- oxygen to help you breathe easily
- a ventilator – a machine that helps you breathe
- a medication that kills viruses called remdesivir and/or a steroid called dexamethasone – in some cases
As COVID-19 is caused by a virus, it can’t be treated with antibiotics, which work against bacteria, not viruses. But if you develop a bacterial infection as a complication of severe COVID-19, doctors may give you antibiotic treatment.
Getting a COVID-19 vaccine
Having a COVID-19 vaccine gives you the best protection against the infection, and several different types of COVID-19 vaccine are now available in most countries. They’re safe, effective and reduce your risk of getting and spreading COVID-19.
The vaccine is given as an injection in your arm, and it’s usually delivered in 2 doses – several weeks apart. The exact number of weeks you’ll need to wait between doses varies with the brand of vaccine and the country you live in.
It’s thought that you may still be able to get or spread COVID-19 after you’ve been vaccinated, so you should continue to take steps to stay safe, like wearing a face covering, avoiding close contact with people you don't live with and washing your hands often.
What can I expect after having COVID-19?
Most people recover from COVID-19 within 2 weeks, but this can take longer, especially if you develop long COVID-19.
If you have ongoing symptoms of COVID-19 or are having trouble getting back to normal after having it, speak to a doctor. They can advise you on things you can do to manage your symptoms and put you in contact with any support services you may need.
It’s possible to get COVID-19 again after you’ve had it, so you’ll need to have a vaccine and keep up with the hygiene and social distancing recommendations.
Visit our Coronavirus Hub to find out more about COVID-19.
Your questions answered
Is coronavirus worse than flu?
Coronavirus (COVID-19) and flu are viral infections that affect the airways and lungs, and both are caused by types of coronaviruses. But COVID-19 appears to cause a more serious type of illness in some people and spreads more easily. It’s also thought that people with COVID-19 are contagious for longer than those with flu.
Can you get COVID-19 twice?
Yes, it’s possible to get COVID-19 more than once. It’s thought that having COVID-19 does give you some protection (immunity) against the condition, but this protection isn’t permanent, and may only last a few months. That’s why you should continue doing things like washing your hands often and wearing a face covering even if you’ve had COVID-19.
Does chlorine kill COVID-19?
Yes. Chlorine is effective at killing the virus that causes COVID-19. This means that cleaning surfaces with bleach, which contains chlorine, can kill the virus. It also means that swimming in a well-maintained swimming pool that contains approved levels of chlorine is safe. But never use chlorine or cleaning products that contain chlorine on your body as doing so can seriously harm you.
- coronavirus (COVID-19) is a respiratory illness that affects the airways and lungs
- around 1 in 3 people who have it don’t show any symptoms
- its main symptoms include a new and ongoing cough, fever, trouble breathing and loss of sense of taste and smell
- a small number of people with COVID-19 can develop a serious and life-threatening type
- there’s no cure for COVID-19, but being vaccinated gives you the best protection against it