Spooned nails
It could be: Anemia or lupus. Do you have a depression in the toenail deep enough to hold a water droplet? Also known as koilonychias, spoon-shaped toenails or fingernails can indicate iron deficiency, as well as hemochromatosis (overproduction of iron), Raynaud’s disease (which affects blood supply to the fingers and toes), and sometimes lupus.
Spooned nails occasionally appear in infants but normalize in the first few years of life. If you notice spooning, contact your physician, who will administer a blood test to identify the exact cause.