Dyspnea and weakness are related to respiratory diseases, cardiovascular diseases, hematologic diseases, neuropsychiatric diseases and so on. 1. Respiratory diseases: the more common are chronic obstructive pulmonary disease, bronchial asthma, acute bronchitis, acute respiratory distress syndrome, respiratory failure and other diseases, which may appear dyspnea weakness symptoms. 2. Cardiovascular diseases: heart failure, pulmonary hypertension, constrictive pericarditis and other diseases, patients may also experience such symptoms. 3. Hematological diseases: patients with severe anemia may also experience dyspnea and weakness. 4. Neuropsychiatric disorders: such as craniocerebral hemorrhage and depression, patients may also experience this symptom. Difficulty and weakness in breathing may also be seen in other diseases, it is recommended to go to the hospital immediately, identify the cause and then actively treat it.