Coronavirus can affect anyone, but people with pre-existing health problems and older people are thought to be at greater risk of developing severe symptoms.Many of the thousands of deaths so far - mostly in China - have involved elderly patients with underlying medical conditions, such as heart disease.
If you have a long-term health condition you may be feeling anxious.
Here's what experts are advising.
Who is at risk?
Having a health condition does not make you more likely than anyone else to contract coronavirus, but it is important that you take precautions to avoid the infection because your symptoms could be more severe should you get sick.
It appears that people who are older, those with weakened immune systems and people who have underlying chronic conditions including, asthma, diabetes or heart disease are more at risk of severe effects.Most people recover from coronavirus quickly after a few days' rest. For some people, it can be more severe and, in rare cases, life-threatening.
Experts say the NHS is well-prepared to care for people with coronavirus. There are a number of hospitals around the UK with specialist facilities.
How can I stay safe?
The main practical thing at the moment is to carry on taking sensible steps to reduce your risk of picking up infections.
The virus is thought to be spread by coughs and via contaminated surfaces, such as handrails and door handles in public places.
Good hygiene can stop the virus spreading between people:
-Cover your nose and mouth with a tissue or your sleeve (not your hands) when you cough or sneeze
-Put used tissues in the bin immediately
-Wash your hands with soap and water often - use hand sanitiser gel if soap and water are not available
-Try to avoid close contact with people who are unwell
-Don't touch your eyes, nose or mouth if your hands are not clean
Should I use a face mask?
The British Lung Foundation says: "We do not recommend using a face mask to protect yourself as there isn't enough evidence to show how effective they are. Also, for people living with a lung condition wearing a face mask can make breathing more difficult."
Do I need to avoid public places?
Most people can continue to go to work, school and other public places.
You only need to self-isolate and stay away from other people if you are advised to by a medical professional.
What should I do if I feel ill?
The symptoms of coronavirus are:
-a high temperature
-shortness of breath
These symptoms do not necessarily mean you have the illness.
If you think you might have coronavirus, you should contact your doctor over the phone or use the online NHS 111 coronavirus service. Do not go to a GP surgery, pharmacy or hospital.
What about my medication?
It is important that even if you are unwell, you continue to take your prescribed medication. If you need to collect prescriptions while unwell, ask a friend or family member to collect them for you.
Prof Peter Openshaw, from Imperial College London, says people should plan to have at least four weeks' supply of medicine.
It might also be a good idea to have some extra food provisions in - but there is no need to panic-buy.