Usage patterns
健康に気をつけるto look after one's health
I exercise every day to look after my health.
健康的な〈物〉healthy (food, lifestyle, etc.)
I try to keep a healthy diet.
健康を保つto maintain good health
A balanced diet helps you maintain good health.
健康を害するto damage one's health
Excessive drinking damages your health.
〈人〉の健康を心配するto worry about someone's health
My mother worries about my father's health.
健康になるto become healthy
It's said that bathing in this hot spring makes you healthy.
Expressions
健康そのものthe very picture of health; health itself