Not everyone is healthy, even though you might think so, according to magazines, television and films.
There are many common chronic illnesses such as asthma, skin conditions (eczema), diabetes, epilepsy. Physical disabilities such as stiffness of limbs, paralysis, are not that uncommon either.

Staying healthy, or coping with health problems often means:-

Accepting and understanding the illness
Dealing with feelings about being ill (like irritation, anger, depression, anxiety)
Taking control of the illness as much as possible, by taking medicine, and changing lifestyle

Ignoring the illness, or or avoiding thinking about it can cause problems.
For example, poor control of asthma causes major problems for teenagers doing sport, or socialising. If severe it can need emergency treatment.

If you have a physical illness, either sudden or long-term, and are having problems dealing with it, you could log-in, and assess your overall strengths and problems.

You may need to deal with other problems first, like anxiety, or depression or anger.
You may then need to alter you life, so that you can do the things you want to do, without the illness stopping you.

To take further control of your illness, you may need to:-

Understand your illness more fully
Get support from a self-help group
Organise and get your treatment more regularly from the professionals involved
Be focused on you achievements,
Be positive about dealing with problems as they happen.