The possible causes of pain in the left back between the scapula and the spine include fasciitis of the back, shoulder joint strain, hyperplasia and degeneration of the spine and scapula. 1. Fasciitis of the back: it may be a localized aseptic inflammation caused by overexertion, exposure to cold, poor posture, and so on. Due to repeated stimulation or pulling of local tissues, congestion and edema are caused, resulting in pain in the middle of the left scapula and spine. 2. Shoulder joint strain: pain in the middle of the left dorsal scapula and spine may be due to adhesion and exudation of soft tissues around the shoulder joint, which will pull the left scapula and surrounding tissues and lead to pain. 3. Hyperplasia and degeneration of the spine and scapula: Pain in the middle of the left scapula and spine can be caused by the irritation of the surrounding tissues due to the hyperplasia and degeneration of the spine and scapula. The pain in the middle of the left shoulder blade and spine may also have other causes, such as myocardial infarction, lung tumor, etc. It is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.