The idiom КАШЛЯТЬ КАК В БОЧКУ describes a severe cough that is | 🇷🇺 Russian from morning till night 🇷🇺

The idiom КАШЛЯТЬ КАК В БОЧКУ describes a severe cough that is difficult to get rid of. Literally: to cough as if to the barrel.
For a week, Sergei coughed terribly and didn't get out of bed.