The blood trapped beneath the nail causes it to turn black or dark in color as it dries and clots. This article will review black toenail symptoms, potential complications, treatment options, ...

Also, the cuticular seal of the nails should be intact, and the nail plate should adhere to the nail bed, says Dr. Thomas ...

If your nails turn blue seek emergency help, especially if you have other symptoms. Below is a chart showing possible nail color changes.