Cardiac reflex zones are different according to each person’s different reflex locations, mainly distributed in the precordial area, the left upper limb, the jaw, the left back scapular area and so on. 1. Pre-cardiac area: when ischemia or injury occurs in the heart, the pain radiates to the pre-cardiac area, which is located above and below the left nipple and behind the sternum. 2. Left upper limb: when angina attack occurs, the pain will radiate to the left upper limb, and the radiation range can be up to the ring finger and little finger, with radiating and involving pain. 3. Jaw: When myocardial ischemia occurs, some patients may radiate to the neck and jaw, with symptoms such as toothache, tightness in the throat or tightness in the jaw. 4. Left back scapular region: When angina attack occurs, the left back scapular region may have discomfort such as pressure and heaviness. If there is pain in the reflex area of the heart, it is recommended to go to the hospital in time and under the guidance of the doctor to avoid delaying the condition.