General causes of hair loss 1, seborrheic alopecia: It often appears in young and middle-aged people, showing thick oily secretion on the scalp, bright, sparse and thin hair, or dry hair with many dandruff, dullness and thinness. Solution: Pay attention to a light diet, eat less irritating food, eat more fruits and vegetables or take vitamins B6 and B2 orally. 2, pathological alopecia: mainly due to viruses, bacteria, high fever damage to hair mother cells, inhibit the normal division of hair mother cells, so that hair follicles are in a state of shock and lead to hair loss, such as acute infectious diseases, long-term use of certain drugs and so on. Solution: Take more rest, and your hair will grow back after you recover or stop taking medicine. 3, chemical hair loss: harmful chemicals damage scalp tissue, hair follicle cells leading to hair loss solution: do not use irritating hair dyes, perms and inferior shampoo. 4, physical hair loss: hair loss caused by air pollutants blocking hair follicles, harmful radiation and other reasons. Solution: Don't use nylon comb and nylon head brush which are easy to generate static electricity, wear protective cap in the environment with serious air dust pollution and wash your hair in time. 5, nutritional hair loss: malnutrition caused by digestive and absorption dysfunction leads to hair loss solution: strengthen nutrition, eat more fruits and vegetables, kelp, mulberries, walnuts. 6, obese hair loss: a large number of saturated fatty acids produce waste after metabolism in the body, blocking hair follicles and leading to hair loss solution: eat less greasy food and strengthen physical exercise. 7, hereditary hair loss: hair loss is also hereditary, generally male is dominant inheritance, female is negative inheritance. First, the purpose of hair care is to maintain the health of hair, and at the same time, it can overcome dandruff or hair loss. The first way to prevent hair loss is to improve health and prevent diseases. Because both acute infectious diseases, chronic wasting diseases, endocrine disorders, infections, poisoning, skin diseases, etc. may cause hair loss. In particular, excessive brain use, mental stress, or stimulation and trauma have a great influence on premature aging of hair, which often accelerates the speed of hair turning white and hair. Therefore, the rational use of the brain, the regularity of life, and an open-minded, optimistic and happy mind are important conditions for keeping the hair fit. Secondly, frequent washing and massage are also good ways to care for hair. Hair is exposed to the body for many years, and it will be stained with a lot of dust every day. Even if you wear a hat, it will affect the hygiene of hair because of the continuous accumulation of sebaceous gland secretions and the continuous shedding of scalp. Therefore, shampooing is not only for cleaning, but also for the health of hair. It is best to wash it once a day if you can. Generally, I have to wash it at least once or twice a week. The water should not be too hot when washing, because overheated water is easy to scald the scalp and make the hair brittle and easy to break; Too cold water is not good, which will affect the effect of decontamination and descaling, so it is best to wash your hair with warm water. Do not use alkaline laundry soap when shampooing, and do not use alkali block or alkali powder to wash your hair, because soda ash has the function of degreasing, which can cause dry and itchy scalp and shorten the normal life of hair. Combing hair is a good massage, which can clear the head, improve eyesight, dredge blood vessels, and prevent neurasthenia, arteriosclerosis, white hair and alopecia. People wake up in the morning, take a lunch break and go to bed at night with ten fingers slowly and gently, and comb from front to back to back, rubbing their scalp while combing, or brushing their scalp and hair with a head brush for about 10 minute each time. Persistence is beneficial to prevent or alleviate senile alopecia, and even can achieve the miraculous effect of turning white hair into black hair and hair loss and rebirth. However, the use of dense-toothed combs or excessive combing and massage is harmful to the hair and should be avoided. Third, alcoholism, overeating, partial eclipse and lack of vitamins and minerals are not conducive to hair growth. As early as more than 2,000 years ago, the ancients clearly pointed out: "If you eat too much bitterness, your skin will be wrinkled and your hair will be pulled out ... If you eat too much sweetness, your bones will ache and fall." It shows that the preference for thick taste can lead to premature aging of skin and hair. Therefore, diversification of diet, eating more fresh and light foods and supplementing enough nutrients necessary for hair growth-sulfur, silicon, iron, etc.-are the key techniques for hair care. Fourth, the hair dryer should not be too hot at ordinary times, lesbians should not perm too often, and hair dyes should be used reasonably, which is also very important for protecting hair. In particular, the modern hair dyes with oxidation dyes as the main body, in which hydrogen peroxide will make hair brittle and loose or even fall off due to repeated use. In addition, people who are allergic to phenylenediamine in hair dyes should not use it to avoid adverse effects.