Overview
COVID-19 is an illness caused by a coronavirus named SARS-CoV-2. It affects mainly the nose, throat and lungs, and ranges from a mild cold-like illness to a serious infection that makes breathing difficult.
Symptoms usually begin three to six days after being near someone with the infection and can last up to about ten days. Most people recover at home. Older people, people who have not been vaccinated and people with long-term illness are the most likely to become seriously ill.
Symptoms
The symptoms reported most often are fever, chills and a sore throat. Others include:
- Cough, sometimes with chest discomfort
- Body ache and tiredness
- Headache
- A blocked or running nose
- Loss or change of taste or smell
- Shortness of breath
- Loss of appetite, nausea or loose motions
Some people have no symptoms at all, and other viral illnesses look much the same, so a test is what tells them apart.
When to see a doctor
See a doctor within a day or two if symptoms are getting worse rather than better, if the illness goes past five days without improving, or if the person is pregnant, over 60 or has a weakened immune system. A baby under three months with a fever should be seen the same day.
Causes
The infection is caused by the SARS-CoV-2 virus. It spreads through the air in small particles released when an infected person breathes, talks, coughs or sneezes, and is caught by breathing them in, or by touching a contaminated surface and then the face.
Crowded, closed rooms with little fresh air make it easier to catch, because the particles linger in the air.
Risk factors
- Older age
- Not having been vaccinated
- Diabetes
- Heart disease or lung disease
- Obesity
- A weakened immune system, including from HIV or cancer treatment
- Pregnancy
- Work with close contact with many people, including health care
Complications
Most infections stay mild. In some people the lungs are badly affected and oxygen or hospital care is needed, and an existing condition such as diabetes or heart disease can get worse at the same time.
Some people have symptoms that carry on for months after the infection. This is called post COVID-19 condition, or long COVID, and it can include lasting tiredness, breathlessness and difficulty with memory and concentration, enough to interfere with daily life.
Prevention
- Vaccination, with further doses for people at high risk when a doctor advises them
- Opening windows and doors so that air moves through the room
- A well-fitting mask in crowded indoor places, and around other people when unwell
- Washing hands with soap and water, or cleaning them with an alcohol-based hand rub
- Staying at home and away from others while unwell
- Keeping away from anyone frail or with low immunity for about ten days after a positive test
Diagnosis
COVID-19 is confirmed by testing a swab taken from the nose or throat. A rapid test gives an answer within minutes, and a laboratory test is used when a more sensitive result is needed.
If breathing is affected, a doctor may measure the oxygen level in the blood, listen to the chest and arrange blood tests or a chest X-ray to see how much the lungs are involved.
Treatment
Most people get better at home with rest, plenty of fluids and simple pain relief such as paracetamol for fever and body ache.
Antiviral medicines are used for people at the highest risk of becoming seriously ill, such as those with a weakened immune system, advanced kidney disease or certain cancers. They work best when started early and are given only after a doctor has assessed the person.
People who become short of breath may need oxygen and hospital care, and treatment is then matched to how ill the person is and to any other condition they have.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“COVID-19 is finished. There is no need to think about it any more.”What is true?
Fact
The virus is still going around and still makes some people seriously ill. The World Health Organization continues to advise vaccination, including a further dose for people at high risk, so that their protection is kept up.
Myth“A course of antibiotics is the quickest way to get over COVID-19.”What is true?
Fact
The medicines that act against this virus are antiviral medicines, and they are offered only to people at the highest risk of becoming seriously ill, after an assessment. Most people recover from a mild illness without any specific medicine.
Myth“Only elderly people become seriously ill, so younger adults need not bother.”What is true?
Fact
Age does raise the risk, but so do diabetes, heart or lung disease, obesity, a weakened immune system and pregnancy. People who have not been vaccinated are also more likely to become seriously ill.
Myth“People who say they are still tired months later are imagining it.”What is true?
Fact
Some people develop what is called post COVID-19 condition, or long COVID, with symptoms such as lasting tiredness, breathlessness and trouble with memory that can get in the way of daily work. It is a recognised condition and worth discussing with a doctor.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
How long should I keep away from other people?
Stay at home and away from others while you have a fever or feel too unwell for your usual activities. After a positive test, the NHS advice is to stay at home for five days for adults and three days for children, and to keep away from anyone frail or with low immunity for ten days.
Is COVID-19 just a bad cold now?
For many people it now feels like a heavy cold and settles in a week. It is not the same for everyone. Older people, unvaccinated people, pregnant women and people with diabetes, heart or lung disease or low immunity can still become seriously ill, which is why the warning signs are worth knowing.
I have already had COVID-19. Do I still need a vaccine?
Vaccination is still advised. The World Health Organization recommends a dose for people who have not been vaccinated, and a further dose after six to twelve months for people at high risk. Your own doctor can say what suits your age and health.
The cough and tiredness are not going. Should I worry?
A cough and tiredness often linger for a while after the fever settles. If they last for weeks, or if breathlessness, chest pain or trouble with memory and concentration are getting in the way of daily life, see a doctor, as this may be post COVID-19 condition and can be assessed and helped.
