Subungual Hematoma (Bleeding Under Nail): A subungual hematoma is a collection of blood in the space between the nailbed and fingernail. Subungual hematoma results from a direct injury to the fingernail. Symptoms and signs include a dark discoloration under the nail and intense pain. Treatment involves icing and elevating the injured digit, taking pain medications, and draining the blood beneath the nail.