The Direction of Hair Growth: The hair will grow at the direction of Umbrella shape. There is one or several spiral hair whorls on everyone’s vertex or surrounding part between vertex and occipital. The hair whorl is on forehead, the hair will grow upward along the hair whorl. The hairs at both sides and below occipital will grow from up to down. For some people, their hair at back demarcated areas will grow from down to up.

　　Hair Growth Cycle: The growth of hair is periodical, has Anagen (growth phase) and Telogen (resting phase), developed regularly. The growth period can be grouped into three phase, i.e. Anagen, Catagen and Telogen. Generally, the hair Anagen is about 2-6 years, and Catagen is about 2-3 weeks, Telogen is about three months. After Anagen phase, the hair will automatically shed off. The hair growth is closely related to the hair follicles. The existence of hair follicles is the premise to guarantee the hair growth and replacement. During the Anagen, the function of hair follicle is active, the cells at base of hair bulb are divided vigorously, the new born cells continuously are put forward up, when the soft cutin became the hardened protein, so the hair are pushed out of the skin and can be seen by eyes. When the hair is at the end of Anagen, the cells of hair bulb will stop multiply and grow, and put forward to epidermis, and separated with hair papilla, so the hair papilla will gradually retrogressed and disappeared, then the hair follicle will start to crimple, the hair stop growing, this is the Catagen. During Telogen, all part of hair will be senescent, retrogressed and contracted, so the hair will be exfoliated. Before the loss of hair, the outer cell of hair papilla will be kept in original place, regrow and keep connection with hair papilla, so the cells will multiply, and form new hair bulb and hair root, the new hair will reappear.

　　Hair Growth Speed: According to test and counting, the average growth speed of hair is about 0.27-0.4 milimeter every day. Based on the counting, the hair will grow about 1 to 1.5 cetimeters in one month, about 10-20 cetimeters in one year. At the initial phase, the hair grows fastestly, and then it will gradually slow down. When the hair grow about 3 cetimeters long, the hair growth speed will be half of that compared with initial phase, and then the speed will be much more slower. The hair growth speed will be affected by body health and food and other aspects. Generally speaking, it grows faster at night than in the day, faster in spring than in winter, faster the young than the old, faster the female than the male.

　　The Quantity of Hair: Due to the difference of race, the quantity of hair will also be few different, generally, the black race have about 108,000 hairs totally, the yellow race have 110,000 hair totally, the white race have about 140,000 hair totally. Among the normal total of 100,000 hairs, the hairs in Anagen account for about 85-90%, in Catagen about 1%, in Telogen about 9-14%. The hairs in Telogen will be shed off when they are washed, combed, or the scalps are scratched. The average quantity of 50-100 hairs will be shed off for normal people every day, which is normal phenomena.