Fingernail white crescent that nail arc shadow or half-moon mark, which may represent the growth rate of the nail, metabolism fast and slow, but not directly related to health. Fingernail white crescent is mainly located in the end of the nail and finger skin junction, generally accounted for the entire nail 1/10 ~ 1/5, mainly by the nail root, the keratin produced by the nail matrix cells, and its growth rate is closely related to the growth rate of nails, generally the larger the crescent, the faster the nail will grow. The growth of the crescent moon is related to human metabolism, as age increases, the body’s metabolic rate slows down, the growth rate of nails will gradually slow down, so many elderly people’s fingernails crescent moon number of the number will be relatively small, the number of crescent moon, the size of the human body and the health of the body has no direct relationship. For the crescent number is small, small area of people, no need to be too nervous, it is recommended that they go to the regular hospital to improve the basic blood, ultrasound and other tests, except the body organic disease, usually pay attention to balanced nutrition, pay attention to rest, keep a happy mood.