Usually, fever does not lead to a decrease in blood pressure, but on the contrary, fever increases the heart rate and may raise the blood pressure. However, we cannot rule out the possibility of hypotension due to excessive sweating after a fever, or prolonged fever with loss of appetite or too little water in the diet, resulting in insufficient blood volume. Patients should drink more plain water or light salt water, eat more fruits and vegetables, pay attention to rest and ensure sleep to replenish blood volume and relieve hypotension. In addition, the cause of fever is mostly caused by bacterial or viral infections, and severe infections can lead to infectious shock. Patients will have accelerated heart rate, decreased blood pressure, wet and cold skin, and decreased urine output, etc. At this time, they should seek professional medical help as soon as possible and take anti-inflammatory or antiviral treatment. At the same time, rehydration treatment should be given as soon as possible to try to stabilize blood pressure in a short time.