What causes toenails to fall off?

If the nail has been crushed or hit, causing damage to the junction between the nail and the nail plate, causing tissue necrosis at this location, over time, the nail plate can not adhere to the nail bed, and the distance between the nail bed and the nail bed is getting farther and farther, resulting in nail loss. It may also cause onychomycosis. Nail pathogens will destroy the nail components, making the nail very brittle, and slowly powdering, slowly eroding from the front of the nail, resulting in nail loss.