ACET: What is the difference between....?
Sick and Ill
A lot of the time they mean the same thing, e.g. to feel sick or to feel ill. But when used with different words or in different situations, we need to use either ill or sick.
To be terminally ill
To feel ill/to feel sick
To take sick leave
Stop the car, I am going to be sick!
To call in sick
That makes me sick!