What factors can lead to emphysema? This is an issue of concern in daily life. Emphysema is a devastating lung disease that causes breathing difficulties in patients, so it is important to treat the disease in a timely manner, and understanding the causes of emphysema is of great help to treatment. What factors can lead to emphysema? 1. Infection: Infection is one of the most noteworthy factors in the etiology of emphysema. Viruses, bacteria and mycoplasma are important factors in the acute exacerbation of this disease. Viruses are mainly influenza viruses, rhinoviruses, adenoviruses and respiratory syncytial viruses, etc. Bacterial infections with Streptococcus pneumoniae, Haemophilus influenzae, Catamorax and Staphylococcus are common. 2, air pollution: harmful gases in the atmosphere such as sulfur dioxide, nitrogen dioxide, chlorine, etc. damage the airway mucosa and its cytotoxic effect, so that the cilia clearance function decreases, mucus secretion increases, increasing the conditions for bacterial infection, which is also one of the causes of emphysema. 3, protease-anti-protease imbalance: protein hydrolase has a damaging and destructive effect on tissues, and anti-protease has an inhibitory function on a variety of proteases such as elastase. Maintaining the balance between protease and anti-protease is the main factor to ensure that the normal structure of lung tissue is protected from damage and destruction. Increased protease or insufficient anti-protease can lead to the destruction of tissue structure and become one of the causes of emphysema. 4, smoking: the most important of the causes of emphysema, tobacco contains tar, nicotine and hydrocyanic acid and other chemicals that can damage airway epithelial cells, so that cilia movement is reduced and macrophage phagocytosis is reduced. Tobacco and smoke can also increase the production of oxygen radicals, induce neutrophils to release proteases, inhibit the anti-protease system, destroy lung elastic fibers, and induce emphysema formation. The longer the age of smoking, the greater the amount of smoking, the higher the prevalence of emphysema. 5, occupational dust and chemical substances when occupational dust and chemical substances: such as smoke, allergens, industrial exhaust and indoor air pollution, etc., the concentration is too large or exposure to too long, may produce emphysema unrelated to smoking.