Koilonychia
Type: Symptom
Definition
An abnormal nail shape where the nail bed becomes flat or concave, resembling a spoon.
Clinical Details
Chronic and severe iron deficiency can alter the structural integrity of the keratin in fingernails. The nails become thin, brittle, and eventually lose their natural convexity, dipping inward to hold a drop of water. This is a classic, though late-stage, clinical sign of prolonged iron depletion.