The nails of the fingers and toes consist of horny plates (“hard keratin”) and are about 0.5 mm thick. They protect the ends of the fingers and toes from damage and also transmit pressure to touch corpuscles. The finger nails also assist in feeling and grasping small objects. The finger nails grow two to three times faster than the toe nails. In general, nails grow faster in young people and in summer, and slower in old people and in winter. Nails grow at a rate of about 0.15 to 0.4 mm a day. Finger nails grow approx. 1 cm in three months.

Nails consist of the body and the root. The root is located in the nail fold, which is about 0.5 cm deep and covers the first quarter of the nail. The nail rests on the nail bed (nail matrix). The nail plate grows from the rear part of the bed. The whitish-coloured half-moon (lunula) at the edge of the visible part of the nail nearest the finger is also part of the nail bed. In this area, the nail is covered by a thin skin, the cuticle, protecting the nail bed from harmful influences. At the sides, the nail is bounded by the lateral nail fold.

Disturbances in nail growth may be an indication of skin or medical illnesses. If a nail is lost, it takes about 6 months to grow again on the fingers and about 12 to 18 months on the toes, depending on blood circulation.