Normal human nails are half of the third phalanx, not too wide and not too narrow, elastic, not easy to break, and have a certain degree of hardness. The edges are parallel to the flesh, light red, shiny, without spots or bumps, and the nails are mainly composed of proteins. Nail soft, white, thin, easy to bend, easy to break, and cracks, can be seen congenital anomalies and lack of vitamin A, vitamin B, vitamin C, as well as the human body lacks the necessary lack of iron, calcium, zinc and other trace elements, as well as nutritional deficiencies, chronic diseases, etc. are closely related. There is also a long time contact with water in daily life, such as easy to break, such people are less energetic, easy to fatigue, like to sleep, poor resistance to disease, depression, easy to irritability, you can do the relevant tests, such as trace element examination to clarify the cause of the necessary time, it is best to eat more food containing iron, and at the same time must be ingested in order to improve the absorption of vitamin C iron ability.