The nail unit is made up of the nail plate and the surrounding structures. These structures include the nail bed, which underlies the nail and forms the attachment of the nail to the finger; the nail matrix, which is located at the base of the nail and is the site of nail growth; the cuticle, which connects the top of the nail plate to the skin behind it; and the nail folds (the folds of hard skin) at the sides of the nail plate, which is where the skin and nail meet.
Many disorders can affect the nails. These disorders can affect any portion of the nail unit and can impact the appearance of the nail plate itself. Nail disorders can result from:
Last full review/revision August 2007 by Wingfield E. Rehmus, MD, MPH