A crescent moon on the fingernail is a normal physiological phenomenon that refers to newborn or incompletely keratinized keratin. The crescent on the fingernail is also known as the crescent white, is just growing out of the nail, because the middle of the nail grows faster than the two sides, so it forms a half-moon shape on the nail. The size of the crescent is actually related to the growth rate of the nails, which can reflect the speed of human metabolism to a certain extent, but the size and number of the crescent do not have any special health significance. After adulthood, the rate of cell proliferation in the body decreases. In general, most adults only have a nail half-moon on their thumbs and show fingers. Not only that, but there are differences in the size and number of nail half-moons between healthy adults. As there are obvious individual differences in the appearance of crescent whites, but there is no direct relationship with health, for the crescent whites too much or too little people do not need to do too much to deal with, if you are really worried about the crescent whites will affect your health, you can go to the hospital to consult a professional doctor.