Nail changes can be incidental findings, or they can be a manifestation of other changes in a person's health. If there is a specific concern about nail changes, a primary care physician
can examine the nails and help direct a person to seek more specialized care should that be indicated.
Nails are constantly growing throughout a person's life which means that changes in their shape, pattern, and color can sometimes reflect events that occurred while the nail was growing. Leukonchyia is the medical term for white discolorations of the nail.
White lines that run horizontally across the nail bed can be caused by systemic illness such as cirrhosis of the liver; by medications including chemotherapy
agents; by heavy metals like arsenic or lead; or by injury
to the nail matrix.
White spots on a nail or nails is most often caused by trauma or damage to the nail matrix. In children this is usually a side effect of biting at the nails. In adults, trauma to the hands can have a similar effect. It usually takes several weeks for the spots to disappear as the nail completely regrows. White spots that persist in multiple nails over time, without evidence of trauma, can be a sign of zinc deficiency.
Overall, because of the many things that can cause nail changes, it is best to have these concerns evaluated by a physician who can take a medical history in addition to doing an exam.