As Covid-19 is a new virus, experts are still working to understand it.
However, health officials say the most common symptoms of coronavirus infection usually include:
- A dry cough
- A high temperature
- Shortness of breath
Developing these symptoms does not necessarily mean you have the illness and they are similar to other illnesses, such as the common cold or flu.
Some people will not develop all of these symptoms - and some might not even show symptoms at all, experts say.
People with fever, cough and difficulty breathing should seek medical attention, the WHO says.
You should also call NHS 111 if you have travelled to any of the affected countries and have a cough, high temperature or shortness of breath.
Or if you have been in close contact with an infected person.
Public Health England defines close contact as being within two metres of someone for 15 minutes or more or sharing a room for a prolonged period.
The NHS has urged people to stay indoors and avoid contact with other people as, if you have the virus, you risk spreading it to others.
Health experts are warning people not to go straight to your doctors' surgery, over fears people will spread the bug there too - but do seek medical help by calling NHS 111.
If you get a cough, a high temperature, or you feel short of breath, continue to follow this advice.
Do not leave your house without getting advice from a doctor.
The best way to prevent catching any form of coronavirus is to practice good hygiene, health experts say.
In order to reduce your risk of infection, you should:
- Wash your hands often with soap and water, for at least 20 seconds
- Do not touch your eyes, nose or mouth with unwashed hands
- Avoid close contact with people who are sick
If you have cold-like symptoms, you can help protect others by staying home when you are sick and avoiding contact with others.
You should also cover your mouth and nose with a tissue when you cough or sneeze then throw it away and wash your hands.
Cleaning and disinfecting objects and surfaces which you may have touched is also important.