The yellowing of hair may be caused by malnutrition, long-term staying up late, kidney deficiency, and other reasons. It is necessary to go to the hospital for local follicle-related examinations and treat the cause accordingly.

1. Malnutrition: In daily life, excessive dieting for weight loss may lead to a lack of nutrients in the body, which may cause the symptom of yellow hair. It is necessary to choose to eat some high-quality protein and foods rich in vitamins for improvement.

2. Long-term staying up late: If you stay up late for a long time in your daily life and do not get enough rest, it will also be accompanied by the symptom of yellow hair, which needs to be improved through sufficient sleep time.

3. Kidney Deficiency: The yellowing of hair is also related to kidney deficiency, and it is recommended to take medications such as Liuwei Dihuang Wan, Jinkui Shenqi Wan, Zuogui Wan, etc. under medical advice for treatment.

In addition to the above common reasons, it is also possible that it is affected by genetic factors, and it is necessary to deal with the cause accordingly.