Nails are unique structures formed of keratin, just like hair and the superficial skin layers. Nail diseases vary in etiology and morphology.

The normal nail is pale pink in color. The end of the nail that grows off the finger is white because it has no connection with the vascular nail bed which supports the rest of the nail plate. Nails can become discolored because of:

• Smoking tobacco
• The use of dyes such as those used for hair
• Certain medications including some chemotherapy drugs
• Infections of the nail bed
• Injury to the nail bed
• Subungual melanomas
• Silver toxicity, quinacrine toxicity and Wilson’s disease – the nails become bluish
• Several systemic illnesses including liver disease – the nails become white
• Renal failure – the nails become half-and-half