Black Nails or Nail Discoloration

General or Other | Dermatology | Black Nails or Nail Discoloration (Symptom)


The nail color of fingernails and toenails can be associated with some serious health conditions. Nails are common to have a healthy pink color. Fingernail color and condition changes are not usually the primary symptom of a serious disorder. In most cases, patients will appear with other signs or symptoms of disease before an obvious nail changes.

Nail colors can be grouped into black, blue, brown/copper, green, blue-green, grey, yellow, pale, purple or red groups, and each color meaning something different.


Black fingernails can indicate signs of Anemia, B-12 deficiency, bacterial infection, chronic kidney disease, adrenal gland problems, liver disease, cancer or melanomas, silver deposits (heavy metals), trauma.

Black toenails are fairly common among runners, especially those training for long-distance races. Black toenails are caused by constant rubbing of a toe against the front of the shoe. A blood blister forms under the nail and the blister cannot breathe, therefore it takes a lot longer to heal. Another cause of black toenails is fungus, or onychomycosis.

Diagnosis and Treatment

Preventing dark nails involves: never biting fingernails and if possible, keeping them short, washing hands regularly and protect them from cuts and scrapes, especially while doing gardening, cleaning, doing dishes, etc. , consume lots of protein, calcium, and vitamin B. Foods like meats, eggs, dairy products and whole grains, consumed in large quantities can be helpful. Other advice is to take a multi-vitamin tablet regularly. Also, never use nails as tools, as they can get severely damaged in the process.