Generally do not cough but once the cough is strong reasons, common in respiratory tract infection, allergic asthma, drug stimulation and other reasons. 1. Respiratory tract infection: after bacterial or viral infection, respiratory symptoms are easy to appear, resulting in coughing, coughing up sputum, runny nose and other symptoms, if the condition has been relieved, can still be left with the symptoms of bronchospasm, which requires a longer period of time to recover, and should be treated with medication under the guidance of a doctor, such as cefixime capsules, oseltamivir, dextromethorphan hydrobromide, and so on. 2. Allergic asthma: when allergic to certain things can trigger a cough, such as seafood, pollen, dust, etc., should be away from allergens, appropriate to improve immunity. 3. Drug stimulation: the side effects of some drugs can cause irritating cough, such as captopril, furotoxin, etc., you can find a doctor to change the drug or dose reduction. Generally do not cough but once the cough is strong reasons, when there is a violent cough, it is recommended to consult a doctor in a timely manner to clarify the cause of the disease, under the guidance of the doctor for treatment, to avoid blind use of medication, delay the condition.