The half-moon mark on the nail represents the strength of the absorption function, because the development of the half-moon mark is affected by nutrition, environment and physical quality, if the digestion and absorption function is poor, the half-moon mark will be blurred, reduced or even disappeared. Half-moon mark also represents the blood circulation flow rate, if small, is poor blood circulation, to the extreme anemia, half-moon shape will disappear completely. General number of normal people half-moon mark is 8-10, and the thumb must have half-moon mark, where more than 8, the thumb also has half-moon mark, belongs to the hot body, this kind of people more exuberant in the body, strong internal organs function, good health, not afraid of cold. If the number of half-moon marks is small, or even only the thumb has half-moon marks, belongs to the cold constitution. This kind of people more visceral function is low, slow blood running, poor physical quality, usually have a pale face, cold hands and feet phenomenon.