Children lying down dyspnea, may be caused by bronchial asthma, severe pneumonia, acute left heart failure and so on. 1. Bronchial asthma: it will lead to the child lying down dyspnea, often forced to sit to relieve the discomfort, accompanied by coughing, wheezing and other obvious symptoms, some of the children may have sweating, irritability. 2. Severe Pneumonia: Severe Pneumonia causes the baby to be unable to lie down flat and sit up to breathe due to the dysfunction of air exchange in the lungs. 3. Acute left heart failure: children due to a variety of congenital heart disease or myocarditis and other factors, sudden acute left heart failure, often accompanied by dyspnea, sweating, irritability and other symptoms, may have pink foamy sputum. Clinical causes of dyspnea in babies are more, such as large amounts of pleural effusion, pneumothorax, etc. can lead to dyspnea in babies, should promptly call 120 emergency. After admission to the hospital to identify the cause, follow the doctor’s instructions to cooperate with the doctor’s treatment.