Hypovolemia is a series of symptoms that occur in patients due to a decrease in total blood volume and microcirculatory disorders caused by various reasons. The manifestations of hypovolemia are: First, the patient will experience thirst and symptoms of peripheral circulation failure such as decreased blood pressure and cold extremities. The most common type of disease is hypovolemic shock caused by severe dehydration, such as patients with traumatic blood loss, and after blood loss, insufficient blood volume will lead to hemorrhagic shock and even threaten the patient’s life. Second, the patient will experience panic and chest tightness because of insufficient blood volume, the heart will experience compensatory heartbeat acceleration, while the respiratory rate will also accelerate, and the patient will feel panic and chest tightness. If the blood volume is replenished in time, the symptoms of panic and chest tightness will be significantly reduced.