It's hereditary. Then it is related to kidney deficiency. Many teenagers are related to kidney deficiency. At this time, they need to eat more vegetables and pay attention to daily exercise. Getting more sunshine and eating more fruit will improve.
In addition, I read an article (Lu Xu | Counterattack) that I can learn from. This is a true inspirational story. I hope it helps.
People with hair loss should have a light diet. Eat foods rich in vitamin B 1, vitamin B6, vitamin E and protein, such as black beans, soybeans, black sesame seeds, lean meat and potatoes. Don't eat spicy, warm and greasy food. Do not drink strong tea or coffee, and reduce the frequency of washing your hair. Hair loss is not a terrible disease. With the above comprehensive treatment measures, I believe that your hair will not only be rejuvenated, but also darker and more shiny.