Sudden and unbearable stabbing pain in the chest may be related to intercostal neuritis, coronary heart disease, mastitis and so on. 1. Intercostal neuritis: when chickenpox-herpes zoster virus infection and other factors cause intercostal neuritis, can lead to chest pain symptoms, the pain is generally more intense, stinging, burning pain, followed by the distribution of rashes along the affected nerves, blisters. 2. Coronary heart disease: patients generally have coronary artery atherosclerosis, coronary artery stenosis, especially in emotional excitement or strenuous exercise and other triggers, coronary artery contraction caused by myocardial ischemia, can cause chest pain, often accompanied by tightness in the chest, shortness of breath. When the condition is serious and myocardial infarction occurs, the nature of the pain is more intense, for the crushing pain. 3. Mastitis: If you are a woman, you may also be caused by mastitis. Inflammation of the breast tissue after infection can cause sudden stabbing pain in the chest, local tissue redness, swelling, heat and fluctuation. The causes of sudden stabbing pain in the chest are complex, and it is necessary to go to the hospital in time to complete the relevant examinations, identify the causes and then under the guidance of the doctor’s treatment.