The crescent of the nail is the newborn not yet fully keratinized nails, the reason for its formation is mainly due to the rapid growth of the two sides of the nails, but the middle of the growth rate is slow, with the exposure of the nails, it will be in the middle of the nail root, you can see the white crescent. Under normal circumstances, human nails are formed by the nail matrix, the nail matrix is constantly producing new keratinocytes, nails continue to metabolize, newborn out of the keratinocytes from the root of the gradual growth, but the nails in the growth of the two sides of the growth of the fast growth, the middle of the growth of the slower, and therefore in the root can be formed in the shape of a crescent moon. The crescent on the nail is a normal tissue of the human body and a normal phenomenon, whether or not there is a crescent generally has nothing to do with the state of health. As long as the nails are relatively smooth, reddish and shiny in color, and have normal curvature, they are normal nails.