Dry cough for more than two weeks, should be vigilant is due to bronchial foreign body, tuberculosis, cough variant asthma and other diseases. 1. Bronchial foreign body: when the bronchial tube into the foreign body, has been blocked in the respiratory tract can not cough, will cause a dry cough without sputum, and the cough lasts a relatively long time, when the seriousness will affect the normal breathing. 2. Tuberculosis: Coughing for more than two weeks or sputum with blood is a common suspicious symptom of tuberculosis. Tuberculosis is usually characterized by a mild, dry cough or a small amount of mucus sputum. It is accompanied by lethargy, night sweats, loss of appetite and weight loss. 3. Cough variant asthma: It is a heterogeneous disease with high airway hyperresponsiveness, which is often exacerbated or aggravated at night and/or early in the morning, with a predominantly dry cough. In addition, there are other diseases that can cause dry cough for more than two weeks, such as family history of lung cancer, long-term heavy smokers, should be alert to the possibility of lung cancer. If the symptoms do not improve or worsen, it is recommended to consult a doctor, complete the examination, clarify the cause of the disease, and follow the doctor’s instructions for treatment.