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.
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 cough
- a high temperature
- shortness of breath
These symptoms do not necessarily mean you have the illness. "The most important thing for patients is not to be alarmed. It is still more likely that anyone with cold or flu-like symptoms will have the flu or a bad cold, not Covid-19."
If you think you might have coronavirus, you should contact your doctor over the phone. Do not go to a GP surgery, pharmacy or hospital.
If you do experience symptoms, isolate yourself and call for advice. Make sure you eat well, stay hydrated and get plenty of rest.
What about my medication?
It is important that you continue to take your prescribed medication. even if you are unwell. 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’s no need to panic-buy.
Do I need a flu jab?
Coronavirus is an entirely different virus to flu, but flu can also make you sick and can be severe in certain people.
If you have not yet had your flu jab there is still time to get one. People aged 65 and over, pregnant women and children and adults with underlying health conditions or weakened immune systems should get one.
I have asthma. What should I do?
Asthma UK advises: Keep taking your preventer inhaler (usually brown) daily as prescribed. This will help cut your risk of an asthma attack being triggered by any respiratory virus, including coronavirus.
Carry your blue reliever inhaler with you every day, in case you feel your asthma symptoms flaring up. If your asthma is getting worse and there is a risk you might have coronavirus, contact your doctor or the hospital by phone.
I have diabetes. What should I do?
Those living with either type 1 or type 2 diabetes could be at greater risk of more severe symptoms. Coronavirus or Covid-19 can cause complications in people with diabetes.
If you have diabetes and you have symptoms such as cough, high temperature and feeling short of breath, you need to monitor your blood sugar closely and call your doctor or the hospital by phone."
What if I have a different chronic health issue?
Those with underlying medical issues like high blood pressure, lung complaints and weakened or compromised immune systems are more likely to develop serious illness as a result of the disease.
Parents of young people with cancer should speak to the medical team treating their child for guidance on the best course of action to take.
To lower their risk of catching coronavirus, high-risk patients are advised to strictly follow the hygiene guidelines to lower their risk of catching coronavirus.
Those who begin to show symptoms should immediately contact their your doctor or the hospital by phone.
Should pregnant women worry?
There is no evidence yet that pregnant women are a high-risk group. Like anyone, they should take steps to avoid infection.
I'm a smoker. Am I at higher risk?
Deborah Arnott, chief executive of public health charity, Ash, advises that those who smoke heavily should either cut back or try to quit entirely to lower their risk.
"Smokers are more likely to get respiratory infections and twice as likely to develop pneumonia as non-smokers," she said. "Quitting smoking is good for your health in so many ways and smokers should see coronavirus as further motivation to give quitting a go to build up their body's defences now before coronavirus becomes widespread in the UK."
I'm elderly and am concerned - should I self-isolate?
The latest advice is that pensioners currently do not need to self-isolate.
Caroline Abrahams, charity director at Age UK, advises that those with elderly friends and relatives make sure they check on them regularly