High unsaturated iron binding is caused by a lack of iron in the body and causes an increase in transferrin that is not bound to iron, commonly seen in iron deficiency anemia. Only one-third of the transferrin in a normal human body binds iron and transports it to the bone marrow to participate in hematopoiesis and the production of red blood cells. The remaining two-thirds of transferrin is known as unsaturated iron binding. The unsaturated iron binding capacity indicates the amount of transferrin that is not bound to iron. Iron deficiency in patients with iron deficiency anemia is manifested by decreased ferritin, decreased serum iron, and increased unsaturated iron binding capacity. Gastric ulcers, heavy menstruation, low iron intake (in vegetarian populations, etc.), gastrointestinal tumors, and many other etiologies can lead to iron deficiency, which can lead to the development of iron deficiency anemia. It is recommended that patients with high unsaturated iron binding capacity should consult the hematology department in time, and complete relevant examinations such as electronic gastroscopy, colonoscopy, gynecological ultrasound (for women), etc., in order to identify the specific cause of the disease, and then treat the cause of the disease and provide iron supplementation therapy (oral ferrous succinate tablets, etc.).