Human nails are formed by keratinization of dead keratinocytes, and crescent moons are those living keratinocytes that are not dead. The reason why it is curved is that the growth rate of keratin cells is the fastest in the middle, and then decreases to both sides in turn.
Under normal circumstances, the crescent number of human nails is fixed. But in reality, it is normal that some people have more crescent moons and some people have fewer crescent moons. Because everyone's physique is different, the situation of methyl, the substance that produces crescent moon, is also different.
If the methyl group is close to the nail, you can see the dead keratin cells, and there are more crescent moons; And the methyl group on the back, you can't see it, and there are relatively few crescent moons. So there is no saying that the more new moons, the healthier. There are many crescent moons, so don't be complacent; there are few crescent moons, so don't worry too much.
Although the number of crescent moons can't reflect the health status, for the same person, the change of the number, shape or size of crescent moons needs attention, which may be a signal of disease.
The crescent-shaped area increases. If in a short time, the area of the crescent on the finger increases, it may be hyperthyroidism, that is, hyperthyroidism. There is hyperthyroidism in the fruit, which not only affects the crescent moon, but also causes symptoms such as decreased sleep quality, abnormal mental excitement and easy sweating. It is necessary to go to the hospital for examination in time.
The new moon soon disappeared. This is also a symptom of this disease. Contrary to hyperthyroidism, it may be hypothyroidism, slow metabolism of old and new, slow growth of nails, and the crescent moon will become smaller and smaller if it is easily covered by armor, or even invisible.
In addition, when the circulatory system and nutrient supply of human body have problems, the edge of the crescent moon will become blurred. If some trace elements are missing, the color of the crescent moon will also change. Under normal circumstances, the crescent moon should be milky white. If it turns black, gray and purple, it may be that the functions of spleen, stomach, liver and other organs decline, especially when it turns black, and the body may have more serious diseases.
In addition, it should be noted that vertical stripes on human nails are also normal physiological phenomena. With the increase of age, vertical stripes appear on most people's nails. However, the appearance of vertical stripes is not necessarily related to gastrointestinal diseases. When you get older, your body will get worse in all aspects, and so will your nails, resulting in vertical stripes.
Note: The picture comes from the Internet.