5 Serious Health Problems Your Nails Could Be Trying to Warn You About

4. Dark Lines Under the Nail – Possible Melanoma

A dark stripe or line running vertically under the nail should never be ignored. This can be a sign of subungual melanoma, a rare but dangerous type of skin cancer. If you notice dark stripes—especially if they widen or change—see a doctor immediately.

5. Deep Ridges or Pitting – Autoimmune Conditions

Small dents or pits in the nails can be associated with psoriasis or alopecia areata, both autoimmune conditions. Deep horizontal lines, known as Beau’s lines, can also appear after a serious illness, high fever, or severe stress.

When Should You See a Doctor?

If you notice sudden changes in your nails that don’t improve within a few weeks, it’s best to consult a healthcare professional. Your nails can’t diagnose health problems by themselves, but they can provide important early warning signs that something isn’t right.