If you feel intense pain in your chest, exhale and return to the surface immediately.

如果你觉得你的胸口剧痛，立即呼出气回到表面。

youdao

Feeling very stuffy time I hug you in my chest, when your tear remains time I make up the pain in here, likes sending out in this moment attentively feels gently.

感觉很闷时候我抱你在我胸口，当你泪留的时候我在这里补痛，爱散发的温柔在此刻用心感受。

youdao

If you have acute pericarditis, the most common symptom is sharp, stabbing chest pain behind the breastbone or in the left side of your chest.

CNN: Pericarditis