Dr Phil Kieran: Is there anything we can do to save my son's injured toenail?

"If your son’s bruise is large enough, it can cause the nail to separate from the underlying nail bed. This is what causes the nail to fall off."

Trauma can lead to bruising or injury to the nail bed, which may be visible on the surface or located under the fold of skin at the base of the nail.

My teenage son plays a lot of sports and recently injured his big toe in a football match. He has recovered, but a black bruise is growing from the base of the nail. 

Does this mean he could lose the nail? And, if so, is there anything he can do to save it?