Black colored nails can be the result of trauma or infection of the skin. Black colored nails present an ugly appearance to the individual and many times people may get embarrassed.

The major causes for black nails are fungal infection, bacterial infection or hematoma. It can also be due to the conditions of kidney, liver, heart or diabetes.

Fungal Infection

The most common fungi that infect the nails are candidas, non dermatophytes or dermatophytes. In tropic condition candidas and non dermatophytic fungi are commonly seen where as in cold conditions dermatophytic fungi are seen.

Whenever there is moisture and dampness or when the protein called keratin in the nail plate that protects the nails gets depleted by the usage of nail polish remover, glue etc., the fungi starts to thrive leading to fungal infection. As the fungal infection progresses the color of the nails becomes yellow, brown, green and finally turn to black.

When the nail becomes black it indicates that the nail is dead because of the non-availability of oxygen or nutrients from the body. In order to prevent such condition take a good diet and avoid the dampness around the nails. If suffering from infection, start applying teat tree oil on the infected area to get rid of the problem.

Bacterial Infection

In certain condition a bacteria called pseudomonas infect the nails and the infection may occur in between the nail bed and nail plate or between the nail plate and artificial nail coating.

The dark color that develops on the nails is due to the infection and is a result of iron compounds. The bacterium thrives well on dampness and feeds the dead tissues and thus softens the nail plate. If the infection is in between the nail bed and nail plate then it may even lift the nail plate from nail bed.

Darker the color deeper is the infection. In order to treat the infection, soak the affected fingers in a mixture of equal proportion of apple cider vinegar and water for five minutes at least twice a day.

Hematoma

Hematoma is the subcutaneous collection of blood and may result from the trapping of the finger between doors, friction from ill-fitting shoes etc. This trauma cause the nail bed to bleed and this blood get trapped in between the nail plate and nail bed.

If the pain subsides after 24 hours then the injury gets cured on its own but if the pain is increasing there are chances of a fracture. As fungi or bacteria may grow in this trapped blood, hematoma needs proper cleaning. This can be done by a doctor or use a sterilized hot needle to make a small hole on the nail plate to ooze out the trapped blood and pack the nail with some antiseptic.