Medical Dermatology


Nails are composed primarily of keratin, a hardened protein also found in skin and hair. The nail itself consists of several different parts, including the nail plate, nail bed, matrix, lunula, cuticle and nail folds.

  • The average growth rate for nails is 0.1 mm each day; individual rates depend on age, time of year, activity level, and heredity.
  • Fingernails grow faster than toenails. Nails also grow more rapidly in the summer than in the winter.
  • Nails on a person's dominant hand (right vs. left) grow faster, and men's nails grow more quickly than women's, except possibly during pregnancy and old age.
  • Nail growth is affected by internal disease, skin disorders, medications, nutritional status (vitamin, iron or protein deficiency), hormone imbalances, infections and the aging process.
  • See your dermatologist if you suspect a problem with nail growth or appearance; it can be a sign of internal disease, infection or inflammation.