When Do Acrylic Nails Fall Off. Acrylic nails are pretty tough, but if they are not treated gently and respectfully, they will fall off. It could be because of unhealthy nails, allergies, or the medication you are taking.

Use a nail file to rub on your nails so that you can clean the entire acrylic stuff from your nails.
Go to Walmart and buy Acetone, not nail polish remover.
At this point it's an absolute necessity to get your acrylics properly detached to. It is equally important to treat the underlying condition that may have caused the nail to fall off in the first place. Use a nail file to eliminate sharp edges and trim the nail if possible.