What condition is characterized by a blood clot forming under the nail plate?

The condition characterized by a blood clot forming under the nail plate is known as a bruised nail bed. This occurs when trauma or injury to the nail results in bleeding underneath the nail. The accumulation of blood creates a dark appearance, which can sometimes lead to a lot of discomfort for the individual.

In contrast, leukonychia refers to white spots or lines on the nail, typically caused by minor trauma or underlying health conditions, which does not relate to the formation of a blood clot. Hang nails and agnails both refer to the condition of the skin around the nail being torn or damaged, rather than any issue that occurs beneath the nail itself. Therefore, the correct identification of a bruised nail bed reflects a clear understanding of nail anatomy and the effects of trauma on it.