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Black and Blue Nails

A black-and-blue nail is usually caused by sudden or repetitive injury to a toe. This might occur during sports that involve running or stopping quickly, such as tennis or basketball. The injury may also result from a heavy object falling on a toe.


The big toe is most often affected. Bruised, broken blood vessels cause the black and blue colors under the nail. If the condition is the result of a sudden injury, pain may be severe.


Your podiatrist talks with you about your symptoms and physical activities. He or she may palpate (press) the area at the end of the toe to determine the extent of pain. Your toe and foot are examined for any signs of infection. If a fracture or a bone spur is suspected, x-rays may be needed. If small black spots are present under the nail, other problems may need to be ruled out.


If pain is severe, the nail may be removed , or a hole may be drilled in the nail to allow drainage, which relieves the pressure. A local anesthetic may be used. Pain may also be relieved with prescription medications, or by soaking or icing the area. If pain is not severe, you may not need special treatment. The nail can be thinned or left alone to fall off. A new nail should grow to replace it.


Many nail problems can be prevented by wearing the right shoes and trimming your nails properly. To help avoid infection, keep your feet clean and dry. If you have diabetes, talk with your podiatrist before doing any foot self-care.

  • The Right Shoes: Get your feet measured (your size may change as you age). Wear shoes that are supportive and roomy enough for your toes to wiggle. Look for shoes made of natural materials, such as leather, that will allow your feet to breathe.

  • Proper Trimming: To avoid possible problems, try to trim your toenails straight across without culling down into the corners. You can smooth the ends with an emery board.