The reflex action of coughing can cough out some secretions or foreign bodies in the respiratory tract, which is a self-defensive and protective action that helps to keep the respiratory tract clean and unobstructed. Clinically, you can usually cough up sputum in the right way by maintaining a stable mood, taking a slow deep breath, inhaling as hard as you can, then holding your breath for a moment, and finally leaning your body forward slightly and exhaling violently to cough up the sputum in the airway as hard as possible, which can be repeated several times. At this time coughing can use the abdominal muscles to force, when inhaling the abdominal muscles stretch, when exhaling the abdominal muscles violently contracted.