If the heart has indescribable difficulty to suspect several factors: 1. The most common factor is highly dangerous cardiogenic diseases, taking into account the presence of acute coronary syndrome, tension pneumothorax or acute aortic coarctation, pulmonary embolism, etc.. Although the incidence of the above-mentioned diseases is low, but the mortality rate is high, if the above-mentioned conditions must immediately go to the hospital to avoid delaying the disease. 2, heart ischemic diseases will also have heart indescribable uncomfortable, such as coronary heart disease, unstable angina, myocarditis, pericarditis, endocarditis will have such clinical manifestations. 3, respiratory system diseases, such as massive lung infection, pleural effusion, etc., the heart will also have unexplained uncomfortable feelings.