catch a cold – get a cold
I caught a bad cold last week and had to miss three weeks of work.
catch one’s death of cold– become very ill (with a cold, flu etc.)
The little boy was told to be careful in the rain or he would catch his death of cold.
check-up
– a periodic inspection of a patient by a doctor
I went to have my annual check-up last week.
clean bill of health
– a report or certificate that a person or animal is healthy
The doctor gave me a clean bill of health when I visited him last month.
come down with– become sick with, catch
My niece came down with a bad cold and was unable to visit me last week.
couch doctor
– a psychoanalyst who puts his patients on a couch
He was sent to see a couch doctor after his continued problems at work.
dose/taste of one’s own medicine
– being treated in the same way as one treats others (usually a negative meaning)
Our boss got a taste of his own medicine when people began to ignore him as he had always done to them.
draw blood– make someone bleed, get blood from someone
The doctor decided to draw some blood from the patient to check up on his blood sugar level.