Source:http://linkedlifedata.com/resource/umls/id/C0423820
NCI: Straight elevated lines on the nail surface. Ridges may be vertical (running from the cuticle to the nail tip) or horizontal (running from one side of the nail to the other). Vertical ridges are usually not associated with underlying disorders and tend to become more pronounced with age. Horizontal ridges may be associated with metabolic disorders and malnutrition.,NCI: A disorder characterized by vertical or horizontal ridges on the nails.