Vertical or horizontal ridges on fingernails can mean anything from normal aging to malnutrition. In order to determine the cause of fingernail ridges, an examination of lifestyle, diet and overall health is necessary.
MedicineNet explains that fingernail ridges often accompany dry and brittle nails. Malnutrition is a common cause of fingernail ridges, and their presence could be indicative of a serious deficiency in one or more nutrients. Vertical ridges are the most common type, but horizontal ridges often occur as well and can be caused by different factors. Trauma to the nail bed can result in nail ridges as the normal formation of the nail is disrupted and warped. The Huffington Post describes nail ridges as a common sign of aging, especially for women. When the nail matrices atrophy, ridges can form much like wrinkles on skin. While this is far more likely to be the cause than is malnutrition, experts still recommend that anyone concerned about nail ridges consult their dermatologist for a professional medical opinion. While multiple ridges are normal, doctors also caution patients to look out for a single vertical ridge. A single vertical ridge is indicative of a tumor underneath the nail bed that is putting pressure on the nail.