Question
My mother-in-law has a fingernail that continuly splits (vertically). She has had the problem for months and it won't grow out. Any ideas as to why this is occuring?

Answer
It is probably splitting like this due to her age. As we age, the nail plate begins to dry out because the body does not produce the same levels of oils and moisture to keep the nail plate hydrated. the nail plate grows forward on the nail bed upon a series of rails and grooves much like a train rides forward on its tracks. The rails are on the nail bed and the grooves are on the underside of the nail plate. As the nail plate becomes dried out with age, the rails can enlarge and push upward through the nail plate, almost cutting it into two (or more) sections. Sometimes, the damage ie permanent and the nail will always split. She can get a silk wrap applied to that nail to keep it from splitting, although this is only a temporary 'fix'. She will have to have the nail overlaid with silk every two weeks.