There are different types of pulmonary atelectasis, and the cause can vary from one type of pulmonary atelectasis to another. Such as bronchial luminal embolism, compression, chronic inflammatory stimulation and so on. 1. Bronchial embolism: Obstructive pulmonary atelectasis is mainly caused by the obstruction of the bronchial tubes, the outside air can not enter the alveoli through the obstructed bronchial tubes, the original gas in the alveoli is absorbed, which leads to alveolar collapse, thus leading to the phenomenon of pulmonary atelectasis. 2. Compressive atelectasis: mainly occurs in the thoracic cavity occupying lesions compressed to the lungs, and lead to the reduction of lung volume, thus causing this phenomenon. 3. Chronic inflammation stimulation: chronic inflammation, the condition is not effectively controlled, easy to develop into scarring pulmonary atelectasis, when the lung parenchyma granulation tissue proliferation, leading to pulmonary fibrosis. In addition, there are passive pulmonary atelectasis, adhesive pulmonary atelectasis, round pulmonary atelectasis and so on. Patients with pulmonary atelectasis are advised to go to a regular hospital in time to avoid delaying their condition.