Coronavirus (COVID-19): Symptoms, risk factors and treatment

7th July, 2022 • 13 min read

What is COVID-19?

First seen in humans at the end of 2019, COVID-19 is an illness that affects your airways and lungs (a respiratory disease). It’s caused by a virus called SARS-CoV-2, which is a type of coronavirus.

Viruses also change over time and different ‘variants’ can appear, which can lead to changes in the way the virus infects people and the symptoms it causes.

Since the SARS-CoV-2 virus was discovered, several new variants have been identified, including the Delta and Omicron variants, and Omicron subvariants (BA.4 and BA.5). More are likely to appear as time goes on.

Read on to learn more about COVID-19, including symptoms, risk factors and treatment, and what you can do to avoid getting it.

Is COVID-19 the same as coronavirus?

Coronaviruses are a large family of viruses that can infect humans and animals. Many coronaviruses only cause mild infections, such as the common cold.

However, some can cause more severe illnesses, such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and now COVID-19.

What are the symptoms of COVID-19?

COVID-19 affects different people in different ways. But most people have a mild to moderate illness that gets better without medical treatment.
There are a number of possible symptoms, which can vary from person to person. And variants of the virus can cause different symptoms. But in many cases, symptoms are similar to those of other respiratory diseases, such as a


Symptoms of COVID-19 can include:

  • high temperature (
    ) or chills
  • a new, continuous cough
  • loss of or change to your sense of taste or smell
  • shortness of breath
  • tiredness (fatigue)
  • muscle aches and pains
  • headache
  • sore throat
  • runny or blocked nose
  • not feeling like eating (loss of appetite)
  • loose, watery poos (
  • feeling sick (
    ) or being sick (

If you’re infected with the original variant of the virus, it takes an average of 5 to 6 days for symptoms to show. But symptoms can appear any time between 2 days and 2 weeks after infection. Evidence from March 2022 suggests it’s more common to get symptoms sooner with the Delta or Omicron variants – within 3 or 4 days.

It’s also important to note that not everyone gets symptoms. In fact, it’s thought that as many as 1 in 3 people who get COVID-19 have no symptoms (asymptomatic) – but they can still infect other people.

What is severe COVID-19?

Most people who have COVID-19 will get a mild or moderate illness, with none, some or all of the symptoms mentioned above.

However, a small number of people become more seriously ill, with what’s known as severe COVID-19. This can cause symptoms such as difficulty breathing, chest pain, confusion, and mobility and speech problems. In some cases, severe COVID-19 can lead to complications such as

, and death.

You’re more at risk of severe COVID-19 if:

  • you’re unvaccinated – or aren’t up to date with any
    booster vaccinations
    you’re entitled to
  • you’re older – particularly if you’re over 65
  • you’re
    overweight or obese
  • you smoke
  • you have a weakened immune system or are having (or have had) medication or treatment that suppresses your immune system
  • you are pregnant

Certain health conditions also increase your risk, including:

Read more about

severe COVID-19

What is long COVID?

Most people with COVID-19 get better within a few weeks. But some people get symptoms that last for weeks or months after the infection has gone – a condition known as long COVID.

Anyone who’s had COVID-19 can get long COVID, even if they had mild or no symptoms when they had the initial illness. It’s not yet understood why some people get it and others don’t.

Read more about

long COVID

How can I cut my risk of getting COVID-19?

COVID-19 is spread through tiny droplets that an infected person releases into the air when they breathe, cough, sneeze or talk. If you breathe in these droplets, you can get infected.

You may also get COVID-19 if you touch your eyes, nose or mouth after touching a surface or object that is covered in droplets from an infected person.

Being in close contact with an infected person increases your chances of catching the virus, whether or not that person has symptoms. The risk is highest in crowded, indoor places, where you’re likely to be in close contact with lots of people.

You can reduce your risk of catching or spreading COVID-19 by:

  • getting a COVID-19 vaccine and any booster jabs (see below)
  • avoiding contact with people who are ill
  • meeting up with people outside rather than indoors
  • opening windows and doors to let in fresh air if meeting people inside
  • wearing a face covering when you’re around other people indoors, particularly in crowded places (read about the
    best face masks for COVID-19
  • covering your mouth and nose if you cough or sneeze
  • washing your hands regularly with soap and water
  • using an alcohol-based hand sanitiser when soap and water aren’t available
  • not touching your eyes, nose or mouth if your hands aren't clean
  • staying at home if you feel unwell

The COVID-19 vaccine

Having a COVID-19 vaccine gives you the best protection against COVID-19, and several different types of safe and effective vaccine are now available in most countries.

The vaccines are given as an injection in your arm, in either 1 or 2 doses, several weeks apart. Many countries also offer extra ‘booster’ doses several months after this, because the vaccines’ effectiveness wears off (wanes) over time.

Exactly when and how a vaccine is given will vary depending on the type of vaccine and the current guidelines in place where you live.

While the vaccine reduces your risk of both getting or spreading the virus, you can still get COVID-19 after you’ve been vaccinated. But the vaccine also reduces your risk of getting seriously ill if you do get infected.

After vaccination, it’s still a good idea to take other steps to avoid infection – such as letting in fresh air when meeting people indoors, and wearing a face covering in crowded indoors spaces.

Read more about

COVID-19 vaccines

When to see a doctor about COVID-19

You can usually manage COVID-19 symptoms at home. But an infection can sometimes become more serious, so it’s important to keep an eye on your symptoms.

You should call an ambulance or go to your local emergency department if you have COVID-19 symptoms and:

  • you feel so out of breath that you can’t talk normally, or have trouble breathing when you stand up or move
  • your breathing suddenly gets worse
  • you’re coughing up blood
  • you faint or collapse
  • you feel cold and sweaty, and have blotchy or pale skin
  • you feel confused, very sleepy or worked up (agitated)
  • you can’t pee, or are peeing much less than you normally do
  • you have a rash that looks like bruises or bleeding under the skin

You should call a doctor for advice if you have COVID-19 symptoms and:

  • you’re pregnant – you may need assessment and/or treatment, so speak to your doctor, midwife or maternity team
  • your symptoms get worse or you’re worried
  • you still feel unwell after 4 weeks

When to see a doctor if you’re at high risk

If you have a condition that puts you at highest risk of getting severe COVID-19, you may be able to have new treatments if you test positive and have symptoms.

In the UK, this will be an antibody or antiviral medicine, which can reduce your risk of becoming seriously ill. You should have been contacted if you’re eligible for these treatments. (If you think you’re at high risk and you haven’t heard anything, speak to your doctor or specialist.)

You may be able to have these treatments if you’re aged 12 or older and have:

  • a condition or treatment that makes you more likely to get infections (immunodeficiency) – such as medications that suppress your immune system. If you’ve recently stopped taking these (within 12 months), speak to your doctor
  • HIV or AIDS
  • cancer – or if you’ve had a cancer removed in the past 12 months or had certain types of chemotherapy or radiotherapy in the past year
  • an organ transplant or stem cell transplant
  • Down’s syndrome (or any genetic disorder known to lower the immune system)
  • sickle cell disease, thalassaemia, or other diseases of the blood or bone marrow (haematological diseases)
  • blood cancer – or have been treated for blood cancer in the past 24 months
  • myeloma
  • chronic kidney disease stage 4 or 5
  • a severe liver condition – such as cirrhosis
  • a neurological condition – such as multiple sclerosis, motor neurone disease, Huntington’s disease or myasthenia gravis
  • an autoimmune or inflammatory condition – such as rheumatoid arthritis or inflammatory bowel disease (IBD)

For these treatments to be effective, they need to be given as soon as possible after you become infected.

In the UK, if you’re eligible for treatment, you should have been sent some lateral flow tests (

see below
, so you can test yourself quickly if you have symptoms of COVID-19. You can also order tests from the
UK government website
or by calling 119. (You should use lateral flow tests from the government, as lateral flow tests you can buy elsewhere can’t be registered.)

If you test positive, you should

report your result online
or by calling 119, so you can be contacted about treatment. You should be contacted within 24 hours. If you haven’t heard anything after 24 hours, contact your GP or call NHS 111. Check the
NHS website
for more information.

How is COVID-19 diagnosed?

There are 2 main tests that can show if you currently have COVID-19:

  • lateral flow tests – these ‘rapid’ tests can be done at home and give quick results, usually within half an hour
  • PCR tests – these tests have to be sent away to a lab to be checked, so can take several days to give results (but they’re more accurate than lateral flow tests)

However, in the UK, you’re no longer advised to get tested for COVID-19, even if you have symptoms. And most people can’t get free tests.

You can still get free lateral flow tests if:

  • you’re eligible for COVID-19 treatments (
    see above
  • you’re a health or adult social care worker
  • you’re going into hospital for treatment

If you want to take a test, but you’re not eligible for free tests, you can buy PCR or lateral flow tests from some pharmacies and shops, or online.

What should I do if I have symptoms or test positive?

In the UK, the current advice is to try to stay at home and avoid seeing other people.

You’re advised to do this if you:

  • have tested positive for COVID-19 – you should avoid other people for at least 5 days
  • have COVID-19 symptoms, and you have a fever or you feel too ill to follow your usual day-to-day routine – you should avoid other people until you don’t have a temperature and you feel better

Remember that it’s especially important to avoid contact with people who are at higher risk of severe COVID-19. You’re advised to not see these people for 10 days after you test positive for COVID-19.

How is COVID-19 treated?

If you don’t have severe COVID-19, you can usually look after yourself at home. Self-care measures to treat symptoms include:

  • getting lots of rest
  • drinking lots of fluids to stay hydrated
  • opening a window to cool your room
  • taking
    simple painkillers
    – if you have a fever, headache or aches and pains
  • taking honey or asking a pharmacist for advice – if you have a cough
  • sitting upright, leaning forward slightly and slowly breathing in through your nose and out through your mouth – if you’re feeling breathless

Most mild cases of COVID-19 get better on their own within a few weeks, although this can take longer in some cases, or if you have long COVID.

As mentioned above, you may be offered an antibody or antiviral treatment if you're at high risk of getting very ill with COVID-19.

Treating severe COVID-19

If you have symptoms that suggest severe COVID-19, you may need to be treated in hospital. Treatment won’t cure the infection itself, but will help to manage the symptoms and any complications.

Treatment for severe COVID-19 may include:

  • oxygen to help you breathe more easily
  • medications that kill the virus (antivirals)
  • medications that help your body fight the virus and help stop your immune system from overreacting (monoclonal antibodies)
  • a steroid medication to help reduce inflammation (dexamethasone)
  • a machine that helps you breathe (ventilator)

COVID-19 is caused by a virus, so it can’t be treated with

– these treat infections caused by bacteria. However, if you get a bacterial infection as a complication of severe COVID-19, you may have antibiotic treatment.

It’s important to tell your doctor if you could be pregnant, as some treatments aren’t recommended during pregnancy.

COVID-19 is caused by a virus, so it can’t be treated with

– these treat infections caused by bacteria. However, if you get a bacterial infection as a complication of severe COVID-19, you may have antibiotic treatment.

What can I expect after having COVID-19?

Many people with COVID-19 feel better within a few days or weeks of infection, and most people will recover fully within 12 weeks. But it can take longer, especially if you develop long COVID.

If you still have symptoms more than 4 weeks after being infected, or you’re concerned, speak to a doctor. They can offer advice about managing your symptoms, and put you in contact with support services if necessary.

You should also bear in mind that you can get COVID-19 more than once – read more about

coronavirus reinfections

Visit our

coronavirus hub
to find out more about COVID-19.

Your questions answered

  • Is COVID-19 worse than flu?

    Answered by:Dr Roger Henderson

    COVID-19 and flu are both viral infections that affect the airways and lungs, and both are caused by types of coronaviruses. But COVID-19 appears to cause more serious illness in some people, and it spreads more easily. It’s also thought that people with COVID-19 are contagious for longer than those with flu.

  • Does chlorine kill COVID-19?

    Answered by:Dr Roger Henderson

    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 this can seriously hurt you

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.