Deep coma is the most serious coma, which is divided into superficial coma, moderate coma and deep coma. In addition to the lack of response to external stimuli, deep coma is accompanied by changes in reflexes, such as weakened deep reflexes, unstable vital signs, such as high and low blood pressure, and disturbances in respiratory rhythm. If deep coma is not treated urgently and the condition does not improve, the next step is death. Coma is when the human brain loses its response to the second human signal system, i.e., to human speech, and it is called coma. If the patient cannot wake up no matter what kind of stimulation is used, even if it is strong, it is called coma.