The so-called signs refer to the objective examination of the patient’s symptoms, such as jaundice, swelling of the hands and feet, etc. In medicine, vital signs usually refer to the four items of temperature, pulse, respiration and blood pressure. If you can not determine whether the patient still has signs of life, the easiest way is to observe the pupil (i.e., the black part of the center of the eyeball), with a flashlight (to focus the light) to shine here, the pupil will be quickly narrowed, is a normal phenomenon, medically known as pupil-to-light reflex. Normal adult pupil diameter in natural light is about 2.5 ~ 4mm, young children and the elderly slightly smaller. If you find that the patient’s pupils are dilated, it is a sign of life-threatening conditions, and you need to call for help. Hou Tao, Department of Liver Diseases, Wuhan Medical Treatment Center.