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• Mee’s lines are transverse white bands that frequently affect multiple nails, and are classically associated with arsenic poisoning.
• Children and active adults commonly have one or more white lines or spots on one or more nails, a condition known as leukonychia.
• Changes in the color of the moon (lunula) can be revealing—heart failure can turn it red, while tetracycline therapy can make it yellow.

*Source: Nail Abnormalities: Clues to Systemic Disease by Robert S. Fawcett, M.D., M.S., Sean Linford, M.D., And Daniel L. Stulbert, M.D., published by the American Academy of Family Physicians (aafp.org)