What Your Fingernails Reveal About Your Overall Health

3.Dark Lines Beneath the Nail

Dark lines under nails can result from trauma, but unexplained streaks might signal skin cancer. Known as melanonychia, these lines are concerning if they appear on a single nail or change over time. Subungual melanoma is a serious concern, and early detection is crucial. Any new or widening dark line should be evaluated by a doctor promptly.