COVID-19 disease, symptoms and variants
Learn about COVID-19, how it spreads, who is at risk, what to do if you think you have it, and what resources and support are available to you.
COVID-19 is the disease caused by the coronavirus, SARS-CoV-2.
Coronaviruses are a large family of viruses that cause respiratory infections. These can range from the common cold to more serious diseases.
How COVID-19 spreads
COVID-19 is a new disease, so there is limited natural immunity in our community. This means that COVID-19 can spread quickly.
The virus is usually spread from person to person by:
- close contact with an infectious person
- contact with droplets from an infected person’s cough or sneeze
- touching objects or surfaces that have droplets from an infected person, and then touching your mouth or face.
Symptoms of COVID-19
Symptoms of COVID-19 can range from mild to severe. Some people recover easily, and others get very sick very quickly. If you test positive for COVID-19 you may experience:
- sore throat
- shortness of breath.
Other symptoms include:
- runny nose or congestion
- headache or fatigue
- muscle or joint pains
- nausea or loss of appetite
- diarrhoea or vomiting
- temporary loss of smell or altered sense of taste.
COVID-19 symptoms are similar to some common illnesses, such as colds and flu, or allergies.
See our COVID-19: Identifying the symptoms fact sheet.
You can use our COVID-19 symptom checker to find out if you need to get tested, or seek medical help.
Viruses naturally change or mutate. This can lead to what is known as a variant to the main virus strain. This generally happens where there is a large amount of community transmission.
There are currently 13 named variants of SARS-CoV-2, the virus that causes COVID-19. Some previous variants of concern were declassified as a variant of concern once further data was available.
The WHO has identified the variants of concern as:
- Alpha – first found in the United Kingdom
- Beta – first found in South Africa
- Delta – first found in India
- Gamma – first found in Brazil
- Omicron – first found in South Africa.
Most people who test positive for COVID-19 recover completely, but some people may develop long COVID.
Long COVID is where symptoms of COVID-19 remain, or develop, long after the initial infection – usually after 4 weeks. Symptoms of long COVID can last for weeks or sometimes months, and include:
- extreme fatigue (tiredness)
- shortness of breath, heart palpitations, chest pain or tightness
- problems with memory and concentration
- changes to taste and smell
- joint and muscle pain.
It is not yet known how long symptoms of long COVID will last. In a large survey of people in the United Kingdom who had COVID-19, nearly 10% of people reported at least one symptom 12 weeks after their initial infection.