The clinical features of nail dystrophies depend on the part of the nail that has been damaged. Due to the important functions of fingernails and toenails, any abnormality of the nail causes impaired function of the hand or foot. Moreover, the aesthetic aspect of the nail may affect employability, self-esteem, and interaction with other people. Because the nails are often difficult to treat, cosmetology may be an effective support to medical treatment. Nail cosmetics may help the patient to cope with his or her nail dystrophy while waiting for treatment to show its efficacy. It may also be the only choice to hide nail dystrophy where the nail is irreversibly damaged. Nail cosmetics may also function at treatment for onychtillomania, nail biting, and nail ingrowing.