Stabbing pain below the clavicle above the left chest may be caused by coronary artery disease, pneumothorax, pleurisy and other diseases, and patients should seek medical attention to clarify the cause of the disease and then treat it. 1. Coronary heart disease: narrowing or blockage of the coronary artery supplying blood to the heart causes heart pain, chest tightness, shortness of breath, squeezing sensation and tingling in the left chest above the lower part of the clavicle, which is mostly seen in people around the age of 50 years old, and can be treated with medicines such as nitroglycerin and sorbitol isonitrate. 2. Pneumothorax: trauma, pulmonary alveolus and other factors lead to gas into the pleural cavity, the patient will have sudden stabbing pain in the chest, coughing, dyspnea, mostly occurring on one side, this kind of people should be strictly bedridden, when the pain is severe, you can use painkillers to treat, if necessary, chest drainage. 3. Pleurisy: Inflammation of the pleura caused by infection and other factors, patients will have pain in the left chest above the lower part of the clavicle, dyspnea, fever and other symptoms, can be treated with penicillin, erythromycin and other drugs under the guidance of the doctor. The occurrence of the above symptoms should be promptly consulted in the hospital to clarify the cause of the disease. All of the above drugs should be used under doctor’s supervision.