Having black nails can result from several different causes. Understanding them helps you better treat your black nails. Trauma A shock or pressure on the nail can cause blood to accumulate under the nail. This results in a black or blue discoloration. In these cases, it is crucial to treat quickly to avoid complications. To relieve the pain, you can apply a cold compress. This reduces the swelling and soothes the inflammation caused by the trauma. Nail fungus Another common cause of a black nail is a fungal infection. Nail fungus causes discoloration and can also make the nail thick and brittle. Fortunately, there are many natural remedies that can help you fight these infections. You can......