The pain on the left side of the fossa of the heart below the ribs to the back may be due to coronary heart disease, pericarditis and pulmonary embolism, etc., which can be treated by general therapy, medication, surgery and other treatments. 1. Coronary artery disease: Coronary artery disease will cause unstable angina, and the pain will radiate to the back when it is severe. Patients should avoid exertion, take proper rest, and under the guidance of doctors, they can take oral aspirin, metoprolol, clopidogrel, atorvastatin calcium and other medications for treatment. For patients with severe symptoms, they can be treated by implantation of coronary stent surgery. 2. Pericarditis: Pericarditis can also cause pain in the anterior chest, and in severe cases, it radiates to the back, left shoulder and left arm. Patients with respiratory distress should be given oxygen, and ibuprofen should be used for pain relief under the guidance of a doctor, or tramadol if the effect is not satisfactory. When pericardial effusion exists, fluid extraction is needed. 3. Pulmonary embolism: pulmonary embolism can also cause the left side of the chest below the rib cage pain to the back of the symptoms occur, the patient should be under the guidance of the doctor to use anticoagulant, antithrombotic drugs for treatment, such as Favarin, rivaroxaban, urokinase and so on. If the situation is serious it can be treated by placing filters in the lower extremities. The left side of the fossa of the heart below the ribs pain to the back may also be other causes, should be timely to the hospital for examination, a clear diagnosis, targeted treatment.