Malnutrition is divided into first degree malnutrition, second degree malnutrition and third degree malnutrition, and is commonly associated with anemia and decreased immunity and resistance. Grade I malnutrition is a mild form of malnutrition, with weight fluctuating below about 15%-20% of normal body weight. The common condition is a decrease in fat content in the abdomen, buttocks and trunk, but it does not affect the operation of internal organs. In Grade II malnutrition, the subcutaneous fat layer in the abdomen is reduced or disappeared, the cheeks are bony, and the fat layer in the hips and limbs is reduced. The organs do not receive enough nutrients, resulting in abnormal functions, and the immune system is reduced, making the patient susceptible to other diseases. In patients with Grade III malnutrition, almost all subcutaneous fat disappears, and there is no fat layer in the limbs, trunk and cheeks and hips, and bone rows can be seen in the body, and the function of internal organs in these patients is very obviously reduced, accompanied by gastrointestinal and nervous system disorders.