The causes of yellowing and thinning hair are also divided into congenital and acquired differences. The congenital yellowing and thinning of hair is determined by genetics and the difference of human race, there is no good way to treat it, the acquired yellowing and thinning of hair is mostly caused by diseases, such as hypothyroidism, high malnutrition, severe iron deficiency anemia and the first recovery from a serious illness, etc., can lead to a decrease in the synthesis and secretion of melanin by melanocytes in the body, so that the basic material of black hair is lacking, resulting in hair from the original The hair will gradually change from black to yellowish brown or yellowish, and it will be easy to lose hair and cause thinning hair. In addition, improper maintenance of hair, often perm and hot blow dry, washing hair with laundry detergent and alkaline water, over time to damage the hair, resulting in yellow hair, damage to the hair quality, causing hair loss phenomenon. How to check yellowing and thinning hair? The clinical manifestation of yellowing hair is mainly dry, lusterless and yellowish hair. The main symptom of hair loss is greasy hair, like rubbing oil, but also scorched hair fluffy, lack of luster, there are yellowish scales fixed hard to take off, or gray-white scales flying, feel itchy if male hair loss, mainly the front head and the top of the head, the forehead of the hair and sideburns move up, the front head and the top of the hair thinning, yellow, soft, and finally make the top of the forehead a bald or some hair; female hair loss in the top of the head, the hair becomes Thinning, but not completely in pieces of loss. Trace elements in the human body play an extremely important role in the human body, and its lack and excess are closely related to the health of people. The hair trace element test is one of the most economical and scientific ways to predict the health condition.