Fingernails and toenails also change with age. Since nails and hair both contain protein, the nails and hair undergo similar changes. Nails grow more slowly and may lose some of their color. This may cause them to be dull and brittle. They may also appear yellow.
Nails often become very hard, thick, and curved.
This is most noticeable in the toenails. Nails may also break or split from time to time. Sometimes, long straight ridges occur in the fingernails. This is another normal change associated with aging. Hair or nail changes may also occur as the result of infections, illness, nutrition problems, or injury.