18 Health Idioms in English and What They Really Mean [2026]

Health idioms are how English talks about being well or ill without getting too medical or too personal, which suits the British habit of understatement. Instead of listing symptoms, people say they are under the weather or on the mend. This list gives you eighteen with a plain meaning and one natural example each, then the soft, very British ways to admit you are not feeling your best.

Health idioms you will really hear

1. under the weather: feeling slightly unwell. I will skip the gym; I am a bit under the weather.
2. fit as a fiddle: in excellent health. At eighty, my grandfather is still fit as a fiddle.
3. back on your feet: recovered after an illness or setback. A week of rest and she was back on her feet.
4. on the mend: gradually recovering. The doctor says he is on the mend after the operation.
5. alive and kicking: active and in good health. We feared the worst, but the old cat is alive and kicking.
6. a clean bill of health: an official confirmation that someone is healthy. The check-up gave her a clean bill of health.
7. run down: tired and weak, usually from doing too much. Months of overtime had left him run down.
8. at death's door: extremely ill. He looked at death's door with the flu, though he made a full recovery.
9. full of beans: lively and full of energy. The children were full of beans after their nap.
10. on your last legs: about to collapse or stop working. After the marathon, my legs were on their last legs.
11. come down with something: to start to catch an illness. Half the office has come down with a cold.
12. a splitting headache: a very painful headache. Turn the music down; I have a splitting headache.
13. black and blue: covered in bruises. He fell off his bike and was black and blue for a week.
14. pull through: to survive a serious illness or difficulty. It was touch and go, but she pulled through.
15. under the knife: having surgery. He goes under the knife for his knee next month.
16. a picture of health: looking very healthy. Back from the coast, they were both a picture of health.
17. a new lease of life: renewed energy and wellbeing, often after recovery. The hip operation gave my gran a new lease of life.
18. take a turn for the worse: to suddenly become more ill. He was improving, then took a turn for the worse overnight.

The soft British ways to say you feel ill

British English prefers gentle, understated words for being unwell, and they are worth recognising. Off colour and under the weather both mean slightly ill without any drama. Right as rain means completely better again: a good sleep and you will be right as rain. And poorly is a soft, everyday word for ill, used especially about children: the baby is a bit poorly today. All of these keep health talk light, and all belong far more to speech than to writing.

You will remember idioms best if you notice them in real conversation rather than revising a list. Next time someone asks how you are, try one of these. Our family idioms guide covers another everyday theme. And when you want to know where your English stands, a free English level test gives you a clear result on the CEFR scale.