to cough violently; to have a coughing fit
煙を吸い込んで激しく咳き込んだ。
I inhaled smoke and had a violent coughing fit.
咳き込んでいる彼に背中をさすってあげた。
I rubbed the back of the person who was coughing violently.
冬場は乾燥によって喉が弱り、少し刺激があるだけで咳き込む。
In winter, the dry air weakens the throat, and even a slight irritation triggers coughing.