Deep breathing left shoulder pain mainly involves the following aspects: 1, the most common is the strain and injury of the thoracic ribs and intercostal neuritis, deep breathing drives the activity of the injury site and inflammatory irritation pain; 2, frozen shoulder, cervical spondylosis, both of these diseases will appear deep breathing pain; 3, pleurisy of the lungs with breathing movement and breathing deepening, will also appear pain; 4, heart disease , such as myocardial ischemia, coronary artery disease, atypical angina will also appear deep breathing shoulder pain. After the occurrence of the above-mentioned conditions to take brake rest, you can use anti-inflammatory and analgesic drugs, observe a week. If the symptoms are not relieved or other new symptoms appear, you need to promptly go to the hospital for consultation.