Mammals use their nails as weapons, as primitive tools, for grooming purposes, for scratching, and for the removal of infestations. Similarly, humans use their fingernails to help pick up small objects and to scratch itchy skin. Fingernails protect vulnerable fingertips; toenails protect toes from the impact of footwear and external trauma. Nails are also important contributors to the aesthetic appearance of the hands and feet. For the health care provider, nail abnormalities may be the first signal that a systemic disease is present.