be/feel under the weather: feel a little sick

→ He woke up with a sneeze and felt under the weather.

take a turn for the worse: have an illness that gets more serious

→ Later that day, he took a turn for the worse, so he called the doctor.

in bad shape: in very bad health

→ The doctor said that he was in such bad shape that he should go straight to bed.

clean bill of health: information that one’s health is excellent

→ He took some medicine and got lots of rest. After a few days, the doctor gave him a clean bill of health.

the picture of health: in excellent health

→ Now he looks well rested and the picture of health.