It could be hereditary, or diet change, illness, medication, trauma, which would show as the new cells are formed in the matrix, there's lots of reasons that could be the cause. This is where the consultation card comes in useful.
luv Sarah xx
If a nail plate is not so smooth, it has tiny bumps or ridges on it like those on a fingerprint, what is this called and will they grow out?
It is not uncommon for some nailplates to have a slighly 'veiny' apperance, like minute raised lines all over the plate. This is usually the nature of the person's plate and is hereditary and will not grow out.
That is what enhancements are for, to smooth out the surface of the plate and make them look gorgeous ... better than the real thing! Usully this type of plate is very healthy and perfect to work on.