The white of the crescent moon on the nail is also known as the half-moon of the nail. If the half-moon of the nail is missing from the nail, it means that the growth of the nail has slowed down. The nail half-moon is primarily formed by immature, incompletely keratinized nail proteins. In the root of the nail, immature, not fully keratinized nail protein tends to contain more water, refractive strong, the formation of opaque white, that is, the naked eye to see the root of the nail crescent white. Generally speaking, the younger the nail half moon will be more, because the age of young, its metabolism is also fast, including the nail metabolism will also increase, so the nail half moon on the nail will be bigger. But with age, the human body stops developing, the body’s metabolism will also slow down, so the nail will grow relatively slow. So even the elderly, as long as their nutrition is adequate, pay attention to exercise, maintain a high level of metabolism, can also appear nail half moon, but compared to young people or less. Therefore, the slow growth rate of nails is the reason for the loss of nail half-moon, the loss of nail half-moon does not indicate the health of the body good or bad.