Leuconychia or "white nail" is an abnormal whiteness of the nails, either in total, partial (spot) or striate (streaks) forms. It may be congenital or acquired.

Leuconychia may occur spontaneously or after minor trauma.

In association with generalised disease it is usually caused by the hypoalbuminaemia of chronic liver disease. The nail beds become opaque, often leaving only a rim of pink nail bed at the top of the nail. The thumb and index nails bilaterally are the most involved.

The exact mechanism is uncertain - it may be compression of capillary flow by extracellular fluid.

Leuconychia is not unique to liver but can also occur with renal failure, fungal infection, lymphoma or can be congenital.