6. Spoon-Shaped Nails

Nails that curve upward at the edges, forming a spoon-like shape (a condition called koilonychia), may be associated with iron deficiency anemia. If you notice this unusual shape along with fatigue or weakness, consider having your iron levels tested.

7. Clubbing (Rounded, Enlarged Nail Tips)

Clubbing occurs when the fingertips enlarge and the nails curve downward over time. This condition can develop gradually and is sometimes linked to lung or heart disease. Because it often progresses slowly, many people don’t notice it right away.

If you suspect clubbing, a medical evaluation is recommended.