Low blood pressure after surgery needs to see your doctor and nurse as soon as possible to check the cause of low blood pressure. If it is due to not eating and drinking for a long time, with the doctor’s permission, you can drink some clear porridge and sugar water, which will help to replenish the body’s water and can gradually bring the blood pressure back up. If you are temporarily unable to eat and drink, your doctor will give you the appropriate fluids to replenish what your body lacks, such as glucose solution, saline, and compounded sodium chloride. Nutritional fluids are sometimes needed for supportive treatment. Commonly used drugs include compounded amino acids, fat milk, and a variety of micronutrients. If it is caused by anesthesia, it may be necessary to give pressure-raising drugs for treatment, such as dopamine. If it is caused by the loss of blood in the body, it may need to be transfused with human blood albumin, pressurized red blood cells, plasma and so on.