7. Brittle fingernails
Nail breakage, which appears in the later phases of anemia, is a much less common symptom of iron deficiency. This condition is called koilonychia. Koilonychia is a disease of the nails in which the nails become abnormally thin and lose their convexity and take on a flat or concave shape. In the early stages, the nails are brittle and can chip or break easily. This condition begins to appear when the nails fall down and the edges are lifted up to give a spoon-like rounded appearance.