The Nail as a Diagnostic Surface
Your nails grow approximately 3.5 millimetres per month, and every millimetre is a record of what was happening inside your body at the time it formed. A dermatologist reading a nail plate is doing something close to what a geologist does with rock strata, each layer carries a timestamp. Horizontal ridges called Beau's lines, documented in clinical literature since the 19th century, mark the exact point when nail growth paused due to systemic illness, high fever, or severe nutritional stress. Vertical ridges are common with age and iron deficiency. Spoon-shaped nails, called koilonychia, are a textbook sign of iron-deficiency anaemia, a condition that affects an estimated 53 percent of Indian women of reproductive age, according to the National Family Health Survey-5 data. The nail was showing the problem long before the fatigue became impossible to ignore.
