Nail disease is a condition in which the nail surface, shape, color and nail plate are abnormal. The nail surface changes include Beaufort’s line, longitudinal nail crest, sulcus nail midline dystrophy, nail dimples, nail lamellar fissures, and rough brittle nails. Nail shape changes include anticoronal nail, pestle nail, shell nail syndrome, racket nail, nailless nail, pincer nail, etc. The nail color abnormalities include white nail, milli line, Terry nail, half nail, yellow nail syndrome, etc. Abnormal nail plate attachment includes nail detachment, nail separation, nail pterygium, etc. The etiology of nail disease is complex, and the main known pathogenic factors are genetics, infection, immunity, loss, other skin diseases and systemic diseases. The main treatment for nail disease is to address the cause of the disease. The principles of treatment are to remove the causative factors, avoid direct contact with alkaline solutions or immersing the nail in water for a long period of time, and choose appropriate antibiotics and antifungal drugs in case of infection. For nail disease caused by non-disease factors, nail water loss should be prevented and finger (toe) nails should be trimmed at the right time. Patients with nail disease should eat more vegetables and fruits in their daily life to replenish vitamins and strengthen their nutrition, as well as strengthen physical exercise to enhance physical fitness.