Protein-energy malnutrition (PEM) is a nutritional deficiency disease caused by inadequate food supply or disease factors, clinically manifested as wasting (marasmus) and malignant malnutrition syndrome (kwashiorkor). Wasting is the result of a long-term lack of calories, protein and other nutrients in the diet, or the patient has a disorder in the digestion, absorption and utilization of food caused by. This type is characterized by energy deficiency and protein deficiency, and is characterized by progressive wasting, subcutaneous fat loss, edema and dysfunction of various organs. Malignant malnutrition, on the other hand, is characterized by a prominent lack of protein in the diet, while the supply of caloric energy is still sufficient, mainly manifesting as malnutrition edema. However, most patients are in between, and mild chronic protein-energy malnutrition is often neglected, which affects the growth and development of children, immune function, susceptible to disease and not easy to recover. So, what tests should be done for patients with severe wasting “skin and bones”? The following is a brief introduction: 1. Check thyroid binding globulin: Thyroid binding globulin is the binding carrier of thyroid hormone, which directly affects the total serum T3 and T4 content. Further improve the diagnosis rate of thyroid disease. 2, check testosterone: testosterone is the main androgen in human body, 95% of plasma testosterone in adult men comes from testicular interstitial cells, and a small portion comes from adrenal cortex and extra-glandular transformation. In women, it mainly comes from the adrenal cortex, with a small amount secreted by the ovaries. Most of the testosterone in plasma is bound to beta globulin, a testosterone-binding protein, and only a very small amount is free and exerts physiological effects. Testosterone can promote the synthesis of protein and bone matrix and increase the preparation of erythropoietin. Testosterone is the main indicator of androgens. 3, thyroid blood flow imaging: thyroid blood flow imaging is with the imaging agent 99mTcO4-imaging, because it can be taken up and concentrated by the thyroid tissue, reflecting its uptake function, in addition to cardiomyocyte uptake, can also be gathered in the hyperfunctioning parathyroid tissue. The thyroid gland is the largest endocrine gland in the body and its blood supply is very rich. Its blood flow can be reflected by dynamic acquisition of radionuclide flow through the thyroid gland after intravenous ‘projectile’ injection. This is usually done in conjunction with a static image.