Coughing up shortness of breath may be the cause of chronic obstructive pulmonary disease (COPD), asthma, left heart failure, myasthenia gravis, Guillain-Barré syndrome and other causes. 1. Chronic obstructive pulmonary disease (COPD): commonly found in middle-aged and old-aged patients with a long history of smoking, chronic inflammatory response of the bronchial tubes leads to irreversible narrowing of the lumen obstruction, so coughing up shortness of breath, especially when acute exacerbation induced by infection and other factors. 2. Asthma: young patients can not cough up asthma is likely to be due to asthma, this disease and hereditary airway hyperresponsiveness and chronic airway inflammation, usually in contact with dust, dander and other allergens induced by airway constriction spasm. 3. Left heart failure: the left ventricular ejection function is weakened, resulting in blood stasis, elevated pressure in the pulmonary circulation, pulmonary stasis leading to pulmonary dysfunction, so coughing up shortness of breath. 4. Myasthenia gravis: the acetylcholine in the neuromuscular junction is attacked by the autoimmune system, which leads to the signaling obstacle in the neuromuscular junction, and the respiratory muscles and other muscles lose their function, so it is impossible to cough up shortness of breath. 5. Guillain-Barré syndrome: autoimmune disorders and other factors lead to peripheral nerve demyelinating lesions, involving the nerves innervating the respiratory muscles, resulting in respiratory muscle dysfunction, so coughing out of breath. Coughing up shortness of breath may be related to a variety of factors, it is recommended to consult a doctor for a definitive diagnosis.