White toenails describes the condition of having white spots on the toenail or the entire toenail turning white. This condition has multiple causes including injury, infection, allergies and diet.
An example of an injury resulting in white toenail would be an object dropped on the toenail that causes trauma to the nail but does not cause broken blood vessels. Instead the injury produces a white spot underneath the nail. However, the more common cause for white toe nail is a fungal infection in the outermost layer of the nail that results in a discoloration.