There are several possible reasons for white nails: the first one is probably a gray nail, which is due to the formation of nail fungus after infection with a fungus. Nail fungus is formed mainly because the fungus invades the cuticle of the nail and eventually the cuticle becomes degenerate and brittle, while becoming white and thick. There is also the possibility of nail white spots, which is a type of nail dystrophy and is mostly related to the functional state of the nail matrix and the peripheral circulation function is not ideal. In addition, it can also be caused by a deficiency of trace elements, which can cause the nails to turn white and sometimes brittle at the same time.