According to Chinese medicine, this change in the nails is closely related to the low function of the body’s tissues and organs, the destruction of tissue structures, atrophy and other pathological changes. Concave nail, refers to the appearance of some horizontal and vertical lines and spots on the nail, etc. The following describes the typology of concave nails and their diagnosis. 1. Vertical lines: The surface of the nail is not smooth enough and a straight line appears, which usually appears after overworking and overuse of the brain; these vertical lines will be clearly visible when there is a lack of sleep. If the vertical lines persist, it may be a chronic pathology of the internal organs. If not taken care of, as the condition progresses the nails will become uneven and even cracked. 2. Horizontal lines: The horizontal lines on the nails are a record of the lesions that have occurred. In other words, when there are horizontal lines on the nails, there must have been some lesions in the body. Generally speaking, at the beginning, the horizontal lines are only at the very bottom of the nail, and as the nail grows, it gradually moves upwards, signaling that the onset of the disease is getting closer and closer. 3, spots: a small amount of white spots on the nails, usually a lack of calcium, silicon or parasitic disease; white spots in greater numbers, may be a sign of neurasthenia; and yellow dots on the nails, may suffer from digestive system diseases; if black spots on the nails should be careful, the lighter is just overworked, malnutrition, the heavier may be a precursor of gastric prolapse, stomach cancer, uterine cancer.