Staying up late the day before the physical examination will have an impact on the body and will directly affect the results of the examination, more commonly cardiovascular examination, the heart rate will become faster, and there will be premature beats, arrhythmias and other conditions. Staying up late can also lead to changes in liver and kidney function, manifesting as elevated transaminases, transient increases in creatinine or protein in the urine, all of which are stress reactions of the organs due to overexertion. Staying up late the day before the physical examination will lead to changes in blood cells. If you drink less water during the process of staying up late, it will lead to excessive concentration of blood cells, which will manifest as an increase in the ratio of red blood cells and white blood cells, interfering with the normal value, which will be an obstacle and interference for the doctor’s diagnosis and judgment of the examination, delaying the judgment of the patient’s health.