The nails are a type of modified skin similar to hair. They assist in protecting the fingers and toes as well as providing clues for general health. The Harvard Medical Center Family Health Guide notes that the nails reveal health signs and can provide the first symptom of a systemic disease. Nail discoloration usually occurs from injury and fungal infections; however, it also can be a sign of something more serious. A health care provider can assist in diagnosing and treating nail discoloration.
Injury
An injury to the nail is one of the prominent causes of nail discoloration. Nail injuries can be mild to severe and cause varying color changes. These injuries occur most often from chronic nail biting, banging the nails and rubbing the skin behind the nails. MedlinePlus reports that nail injuries also commonly develop from long-term exposure to moisture or nail polish that causes the nails to peel and become brittle.
Nail injuries can cause mild discoloration in the form of white streaks or small white patches on the nails, also called leukonychia. While leukonychia occurs often from injury, it may also be a sign of underlying medical problems such as vitamin deficiencies or heart disease. The nails may also turn black or purple after injury because of blood formation under the nails.
Nail Psoriasis
Psoriasis is a long-term skin condition that causes abnormally fast-growing and shedding skin cells. The rapid production of skin cells occurs from abnormal immune system responses. Psoriasis can occur anywhere on the body, and the nails are a frequent area for the condition. The National Psoriasis Foundation notes that nail changes occur in 50 percent of people with psoriasis and at least 80 percent of those with psoriatic arthritis.
When psoriasis affects the nails, it usually manifests as yellowing or browning of the nails, deformation of nail shape, pitting and thickening of the nails and separations of the nail bed. Nail psoriasis tends to occur with the formation of new nails, and about one-third of those with the condition also have fungal infections, notes the National Psoriasis Foundation.
Fungal Nail Infections
Fungal nail infections occur when fungus infects the fingernails or toenails. Fungus, yeast and mold can cause the condition, and each can affect the nails differently. There are four major types of fungal nail infections, each named for where the infection starts on the nails. Distal subungual onychomycosis is the most common type of fungal nail infection. It starts at the end of the nail bed, where it can cause white, yellow and green discoloration, explains OurHealthNetwork.com.
The three other major types of fungal nail infections are white superficial onychomycosis, candida onychomycosis and roximal subungual onychomycosis. The most common symptoms of fungal nail infections include discoloration, thickened and brittle nails, distorted shape and separations from the nail bed.
