不适 (bú shì): uncomfortable, unwell

After eating seafood from that street stall, I felt unwell in my stomach all night, and went to the hospital first thing the next morning.

During the first few days after moving to the highlands, he kept feeling unwell and got badly out of breath after just a few steps.

Although this medicine can bring down a fever, some people have adverse reactions such as dizziness and nausea after taking it, so it should be taken as the doctor instructs.

My mother always gets carsick on long-distance buses and feels very unwell the whole way, so this time we took the train home instead.