Lying down and feeling breathless, sitting up and being fine may be caused by pulmonary dyspnea, cardiac dyspnea, psychological problems and other factors. 1. Lung dyspnea: Lung dyspnea is commonly seen in bronchial asthma, pneumonia, pleural effusion, etc. The patient will feel dyspnea due to insufficient gas, which may be accompanied by panic, drowsiness, dizziness, fear, etc. The patient may feel that he/she is not breathing well enough. 2. Cardiogenic dyspnea: cardiogenic dyspnea, common diseases include heart failure, pulmonary stasis and other diseases, when the body is lying down, pulmonary stasis will be aggravated, resulting in dyspnea, after getting up, it will be fine, and at the same time in the exertion of the phenomenon of dyspnea will also occur. 3. Psychological problems: may be caused by adverse emotions, such as anxiety, depression and other emotions, may cause lying dyspnea, sit up on the phenomenon of all right. Lying down and feeling breathless, sitting up all right may be caused by other reasons, such as lung malignant tumors, chronic obstructive pulmonary disease, etc. It is recommended to go to the regular hospital for examination, the doctor will be based on clinical symptoms to give the appropriate diagnosis.