When to use body ache in Korean
Korean: 몸살[ mom-sal ]

When to use it
Body ache means your whole body feels sore, heavy, and tired. In Korean, 몸살 is often used when you feel sick or after too much work or exercise. People usually say they "got" body aches, not that one small part hurts.
Example sentences
어제 운동을 많이 해서 몸살이 났어요.
I exercised a lot yesterday, so I got body aches.
몸살이 심해서 오늘 학교에 못 갔어요.
My body aches were bad, so I couldn't go to school today.
비를 맞고 나서 몸살이 났어요.
After getting caught in the rain, I got body aches.
선생님께 몸살이 나서 결석한다고 말했어요.
I told my teacher that I would be absent because I had body aches.
약국에서 몸살약을 샀어요.
I bought medicine for body aches at the pharmacy.
여행에서 돌아온 뒤에 몸살이 나서 집에서 쉬었어요.
After coming back from the trip, I got body aches and rested at home.