Nail Discoloration: Symptoms & Signs

Nail discoloration, in which the nails appear white, yellow, or green, can result from different infections and conditions of the skin. In about 50% of cases, discolored nails are a result of infections with common fungi that can be found in the air, dust, and soil. There are many species of fungi that can affect nails. By far the most common, however, is called Trichophyton rubrum. This type of fungus has a tendency to infect the skin and is therefore known as a dermatophyte. Pseudomonas is a type of bacteria that infects the nail bed and results in a greenish color to the nails. Red or black (that may sometimes appear bruised) nails may result from a hematoma (a collection of blood) under the nail as a result of trauma (including ingrown toenails).

Chronic medical conditions also can affect the appearance of the nails. Specific color changes in the nails can be suggestive of diabetes or of liver, kidney, heart, or lung conditions. This is why doctors pay specific attention to nails during a routine physical examination.

Other, rare causes of discolored nails include the "yellow nail syndrome," an inherited condition that results in slow-growing, yellowing, discolored nails and is associated with lymphedema (swelling of tissues due to the accumulation of fluid) and lung diseases. Nails may also appear lightened to a whitish-yellow color if there has been separation of the nail from the nail bed, termed onycholysis.

The skin, mucous membranes, and nails may appear blue when there is inadequate oxygenation of blood (cyanosis), but this is not true discoloration of the nail itself.

Related Symptoms & Signs

Other causes of nail discoloration

  • Bacterial Infection
  • Candidiasis
  • Chronic Lung Diseases
  • Drug Hypersensitivity (for Example, Tetracycline)
  • Malnutrition
  • Onycholysis
  • Senile Ischemia (Onychogryphosis)
  • Staining From Nail Varnish or Cosmetic Products
  • Trauma
  • Yellow Nail Syndrome

Next Article

SLIDESHOW

Cosmetic Surgery: Before and After Photos of Cosmetic Surgeries See Slideshow

Subscribe to MedicineNet's Skin Care & Conditions Newsletter

By clicking "Submit," I agree to the MedicineNet Terms and Conditions and Privacy Policy. I also agree to receive emails from MedicineNet and I understand that I may opt out of MedicineNet subscriptions at any time.

Medically Reviewed on 9/10/2019
References
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.
CONTINUE SCROLLING FOR RELATED SLIDESHOW