stress. for an instance, when you are angry, you hit your hands towards wall. in that time, do you realize your nails can be affected? but by the time, you will see those white spots on your nails and will feel sorry for yourself. so, try to think before you do for something like this.
can you find other causes of your marks? besides having injuries, one more reason can be infection or allergies caused due to nail products like nail polish, remover and so on. if you are having any medicine on a daily basis, that can also affect your nails. be careful while using artificial nails as they can 