Coronavirus is a respiratory disease which seems to start with a fever, followed by a dry cough. After a week, it leads to shortness of breath and some patients require hospital treatment.
These symptoms do not necessarily mean you have the illness. They are similar to those for much more common viruses, such as colds and flu.
In more severe cases, coronavirus can cause pneumonia, severe acute respiratory syndrome, multiple organ failure and even death.
Older people, and people with pre-existing medical conditions (such as asthma, diabetes, heart disease), are more likely to become severely ill.
The incubation period – between infection and showing any symptoms – lasts up to 14 days, the World Health Organization (WHO) says. But some researchers say it may be up to 24 days.
Regular and proper hand watching is crucial in the fight to avoid picking up the disease, health agencies say.
It is not yet known exactly how coronavirus spreads from person to person. However, similar viruses are spread via droplets, such as those produced when an infected person coughs or sneezes.
So, coughing and sneezing into tissues, not touching your face with unwashed hands, and trying to avoid close contact with infected people are important.
But people who think they may be affected by coronavirus NHS for further advice. They should not go to their GP, or A&E.
If you have come into contact with somebody who may be infected, They should self-isolate and use common sense to avoid contact with people.
Hundreds of new cases are being reported worldwide each day. However, it is thought health agencies may be unaware of many cases.
After starting in China, coronavirus is now spreading fast in countries like South Korea, Italy and Iran.
Four out of five people who contract coronavirus will only experience mild symptoms, a WHO examination of figures from over 50,000 people say.
- 80% develop mild symptoms
- 14% develop severe symptoms
- 6% become critically ill
The proportion dying from the disease appears low (between 1% and 2%) – but the figures are unreliable.
Thousands are still being treated but may go on to die – so the death rate could be higher. But it is also unclear how many mild cases remain unreported – so the death rate could also be lower.