Toenail fall because of 2 reasons one is due to fungus, second is injury. No need to worry, in both cases your toenail can be cured.
Falling of nails due to fungus is called Onychoptosis, which mean “falling nail”. This is caused due to fungus.
Toenail fungus causes your toenails to:
Read more on causes for toenail fungus.
All you can do is practice few nail care tips to prevent fungus invading your toenails.
Here is an image of fungus.
Here are few discussion going on about the same problem.
Second reason falling of nails due to injury
Which is not uncommon too, anyway if you don’t take care of injured nails then you might end up having toenail fungus. Clean the injured part and then apply cream or lotion. You can also try home remedies for toenail fungus like applying Turmeric.