Nail dystrophies of the fingers due to environmental factors and to incorrect manicure procedures are very common and a frequent cause of nail consultation. The fingernails are in fact continuously exposed to exogenous traumas due to mechanical and chemical substance that may induce damage to the soft tissues or to the nail plate and cause different alterations. Some manual professions induce mechanical trauma to the nails, when the fingernails are utilized as tools, for example, in tailors, cooks, leather workers, car repair workers, etc. Beside professional exposure, fingernail damage is induced by common procedures that are often underestimated as a cause of damage: the manicure with application of nail polishes is a frequent cause of nail abnormalities, as can nail biting and chewing. All these causes of nail damage occur often together and are quite difficult to avoid completely: for these reasons, nail brittleness, paronychia, and onycholysis are very difficult to cure. The clinical history is mandatory for a correct diagnosis and management of these conditions: beside the patient’s profession, information on hygienic measures and hobbies should be questioned and type and frequency of manicure. Auto-induced nail disorders usually affect the fingernails: in some cases the patient is aware of the self-induced trauma, while in other cases he/she denies it. These are often patients with mental problems who are difficult to manage.