Your Nails Can Be Window Into Your Health

If you’ve been feeling a little “off” lately but you can’t put your finger on what’s going on you might want to check out your fingernails.

It’s long been known that your fingernails and toenails, made of dead skin cells toughened by keratin, can show the effects of numerous illnesses and disorders.

They are not a definitive diagnostic tool, but certain changes in the nails may be indicative of underlying health issues. Color, texture and rate of growth can all signify issues that warrant consulting your health care professional.

Nail color

  • Pale — Partly or completely white nails can be linked to anemia, dietary deficiencies, trauma to the nail, heart or kidney disease or poisoning.
  • Yellow — This common symptom of fungal infection can signify psoriasis, thyroid disease or diabetes. Wearing dark nail polish also can cause yellowing.
  • White spots or lines — Often due to minor trauma, persistent white spots also could be from a fungal or bacterial infection or an allergic reaction.
  • Dark lines or spots — These can be caused by nutritional deficiency, certain medications or more severe conditions including skin cancer.


  • Brittle or split nails — These can result from thyroid disease, but if the nails are also yellow it could be rooted in a fungal infection.
  • Pitting— Small dents or depressions are a common symptom of eczema or psoriasis and pitting also is associated with alopecia.
  • Horizontal ridges — Injury or illness may have interrupted nail growth, such as diabetes, heart disease or COVID.


  • Clubbing — Nails curve around enlarged fingertips over the course of a few years, often tied to heart, lung or liver disease.
  • Spoon nails — Soft nails that curve upward at the edges are most often tied to anemia or a liver disorder in which too much iron is absorbed by the body.

Changes in Growth

  • Slow or fast growth — Sudden changes may indicate a health problem or nutritional deficiency. Stress or chronic illness can cause growth to slow or stop.
  • Thickened nails — Can be caused by aging but may also indicate a fungal infection or psoriasis.