Bronchitis is often caused by infections of the whistling tract caused by bacteria and viruses and attacks. The main causes of the disease are as follows. Long-term inhalation of air polluted by chemical poisons, dust or industrial waste can lead to the occurrence of the disease; smoking is also one of the causes of the disease, smoking will lead to increased mucous secretions in the bronchi, increasing the chances of infection; meteorological factors are one of the important factors in the development of the disease, a sudden drop in temperature, cold air, inhalation of cold air, the small blood vessels of the lungs are prone to spasm, the ability to defend against the decline is easy to Poor nutrition will make the immune system decline, can not effectively resist the invasion of microorganisms, bacteria and viruses will cause the onset of the disease; allergy is also an important factor, allergic people are prone to the occurrence of the disease. In life, patients should do a good job of disease prevention, reasonable diet, regular work and rest, and develop a good lifestyle. Quit smoking is an important step to promote the recovery of the disease, proper exercise, improve their immunity, cold weather, wear a mask in time to avoid cold air inhalation to stimulate the respiratory tract, at home or at work, must open the windows to ventilate the air. So, the causes of bronchitis are mainly the above aspects, in order to prevent the occurrence of the disease, in life must do a good job of bronchitis prevention, early detection, early treatment, and pay close attention to the changes in the body.