What Black Nails Mean? [Solved]
Hello, iam Jean Terrell, I hope today is better than yesterday. What Black Nails Mean? [Solved] June 29, 2022. A black fingernail is known as a subungual hematoma. It is caused by a build-up of blood under the fingernail. This usually results from an impact or trauma to the finger which can cause considerable pain. In most cases, ice and ibuprofen are sufficient to treat it. What causes vertical black lines on fingernails?...