Hemoglobin content is the amount of hemoglobin contained within each red blood cell in peripheral blood, and hemoglobin concentration is the sum of the amount of hemoglobin contained within all red blood cells in a liter of blood. The most common cause of decreased hemoglobin volume and hemoglobin concentration is microcytic hypochromic anemia. The most common type of anemia in clinical practice is iron deficiency anemia, in which hemoglobin synthesis is impaired due to iron deficiency and insufficient hemoglobin synthesis, resulting in a decrease in the volume of red blood cells and a decrease in the amount of hemoglobin contained within each red blood cell, and a decrease in hemoglobin concentration due to a decrease in the amount of hemoglobin contained within each red blood cell. Patients will show symptoms of anemia such as pallor, dizziness and weakness, panic and chest tightness, etc. They will also show a series of special symptoms such as dry hair, hair loss, brittle and thinning nails, spatulate nails, etc. Generally, iron supplementation medication is given clinically with good effect.