Normal blood test cough old bad may be caused by tuberculosis, allergic cough, cough variant asthma and other diseases. It should be improved by medication and general treatment. 1. Tuberculosis: Tuberculosis can cause cough, and most patients have normal blood count. Patients should take anti-tuberculosis drugs as prescribed by doctors, such as isoniazid, rifampicin, pyrazinamide, etc., and take more rest and avoid exertion during the treatment. 2. Allergic cough: Allergic cough will cause patients to have irritating dry cough, and the routine blood test is usually not abnormal. Patients should take oral dextromethorphan, pentoxyverine and other cough suppressants as prescribed by the doctor. If the symptoms are more serious, nebulization treatment can be taken, commonly used drugs are beclomethasone propionate, budesonide and so on. Patients also need to identify allergens and avoid re-exposure. 3. Cough variant asthma: cough variant asthma with cough as the main symptom, most patients with normal blood routine. You can choose glucocorticoid inhalation therapy, such as budesonide, or intravenous prednisolone acetate and other drug therapy. Normal blood test cough old bad may have other reasons, such as family history of lung cancer, long-term large number of smokers, need to be vigilant about the possibility of lung cancer, need to consult the regular hospital in a timely manner, cooperate with the doctor to improve the examination, standardized treatment, can not be blindly used on their own medication.