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Overview of Nail Disorders

By

Chris G. Adigun

, MD, Dermatology & Laser Center of Chapel Hill

Last full review/revision Dec 2019| Content last modified Dec 2019
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Topic Resources

Many disorders can affect the nails, including deformity and dystrophy, infections, and ingrown toenails. Infections can involve any part of the nail and may or may not change the nail's appearance. Most nail infections are fungal (onychomycosis), but bacterial and viral infections occur.

The nail unit is made up of the nail plate (the hard part of the nail made of the protein keratin) and the surrounding structures. The nail bed is underneath the nail and attaches the nail to the finger. The nail matrix is located at the base of the nail and is where nail growth originates. The cuticle connects the top of the nail plate to the skin behind it. The lunula is the half-moon shape at the base of the nail. The nail folds are the folds of hard skin at the sides of the nail plate where the nail and the skin meet.

Did You Know...

  • Some babies are born without nails, a condition called anonychia.

Causes of Nail Disorders

Some of the causes of nail disorders include the following:

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Spotlight on Aging: Nail Disorders

With aging, nails become dry and brittle and flat or concave instead of convex. They may develop ridges along their length. Nail color may change to yellow or gray. Brittle nails may split.

Toenails require special attention in older people and in people with diabetes (see Foot problems in diabetes) or peripheral vascular disease (see Foot care). Such people may have poor sensation in their feet, which increases the risk of injury when they try to trim their nails. A foot doctor (podiatrist) can help care for their nails to prevent skin breakdown that can lead to infections.

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