Whenever my son or significant half said to me that they are unwell, I will always ask them to tell exactly what's the problem.
To me the word "unwell is not enough or a complete words/sentences they wanted to tell me at time. This is not because I don't understand the word (unwell) but it is rather curious about the underlying cause(s) in which makes them feel unwell at first place.
It is utmost important that they must precisely say how they are general feeling at time. I.e. Headache, tummy ache, nausea etc... By being specific about certain health issue at time would help love ones' panicking or anxiety, whether or not we shall seek medical attention..