Pallor of the nail beds, skin and mucous membranes in anemia is characteristic of all anemic patients. The pallor of the oral mucosa, lid conjunctiva and nail bed is the most obvious. Therefore, the nails of anemic patients will have pale nail beds, nails without luster, nails become brittle and thin, easy to break, and there will also be flat nails. Nails that are specific to iron deficiency anemia have a spoon-shaped concavity, which is also known as an inverted nail, and therefore an inverted nail is a specific nail symptom of iron deficiency anemia.