The precursors of sudden death are manifested in the heart, lungs and brain nerves, as follows: 1. In the heart, the precursors of sudden death are chest pain, chest tightness and shortness of breath, arrhythmia, etc. Chest pain is generally colic or crush-like pain, which lasts for a long time and is difficult to relieve. 2, brain and nerve precursors of sudden death include headache, dizziness, weakness, insomnia and forgetfulness, mental trance, indifferent expression. 3, respiratory precursors of sudden death are mainly asthma attacks. 4, gastrointestinal tract, such as loss of appetite, indigestion and other conditions.