It depends entirely on what is causing the nail plate to separate from the nail bed, and there is always a reason. If the nail plate has thickened, turned yellow and there is apparent debris in the area of separation, then you probably have a fungus infection. If the nail looks very white where it has separated, you may have a yeast (candida) infection. If you wear artificial nails, it could be from either of the above, or you may have become allergic to the products, although the cuticles would be itching and the nail bed would experience a burning sensation. If you work in a bar, you could have an allergic reaction to the acid in the fruits. There are many reasons, so the first thing you should do is to see your physician for a proper diagnosis.