Hidden pain above the left chest does not hurt when you fall asleep, it may be due to costochondritis, soft tissue injury, coronary heart disease and so on. 1. Costal chondritis: a vague pain above the left chest does not hurt when you fall asleep, may be caused by costal chondritis, the disease is divided into non-infectious costal chondritis and infectious costal chondritis, non-infectious costal chondritis is caused by trauma, chronic strain and viral infections, infectious costal chondritis is caused by postoperative infections of pathogenic bacteria. 2. Soft tissue injury: If affected by collision, extrusion, tearing and pulling and other injury-causing factors, it will lead to localized swelling and breakage, which will lead to vague pain in the upper part of the left chest and no pain when the patient falls asleep. 3. Coronary heart disease: when suffering from coronary heart disease, there can be hidden pain in the left chest, after falling asleep, the body’s metabolic rate decreases, the body’s oxygen consumption decreases, so that the pain is relieved. It is recommended to go to the regular hospital in time, under the diagnosis of the doctor, according to the specific results of the examination, targeted treatment.