You will find that most people in China are very healthy but there are precautions that you should take when your traveling abroad. There are different variations of hygiene that vary from place to place so you will have to take precautions on your trip.
The most important thing you should do before leaving home is make a visit to your doctor. Have a thorough checkup especially if you have had a history of heart trouble. On your trip you may have to walk long distances or end up climbing some mountains etc. and should know what your limits should be which your doctor can advise you on. Some of your activities can prove to be very tiring especially if your of the older generation.
Study your health insurance policy to make sure you are covered for overseas visits, if your not then you should talk to your insurance agent about getting an extended policy to cover you while you are there. Don't forget to check on accidental insurance along with your medical insurance. You may never need it but it will give you peace of mind on your trip. Travel insurance will cover you for many other risks such as loss of money, loss of baggage and much more.
An excellent idea would be to go to your doctor and get a copy of your health records such as any chronic ailments you have, allergies, immunization history, your blood type and any eyeglass prescriptions. Anything that could help your doctor overseas to understand your medical history. Having your home doctors address and phone number would also be a great idea. If you get these documents make sure you carry them in a safe place and as close as you can get them if you need them.
If you have prescription medicines make sure you take an ample supply of everything to do you while you are in China. It is better if you leave them in the bottles you got from the pharmacy so they can be identified easily. These should be kept in your carry on for easy access. In addition to your prescription medication you should take medicines to cover any colds you might get and medicines for diarrhea and constipation.
When traveling always take the smallest precautions such as washing your hands frequently, don't eat raw meat or food that is not thoroughly cooked, wash any fruit with purified water and boil it for a few minutes , when possible, and drink only bottles or boiled water. Take your own toiletries as some of your traveling may be off the beaten path and may not have the amenities that your use to. Remember also that some regions of China have very high altitudes which is not good for people with heart trouble. If you prepare for your trip properly then it will be a success. Concentrate on the things you can do and not the ones you can't do and you will have a trip to remember for the rest of your life.