What causes teenage insomnia?

Adolescent insomnia is also more common in clinical practice, mainly due to the following reasons: first, learning competition pressure, especially graduating class students, or college graduates face job hunting, employment, ideological pressure is too large, easy to cause insomnia. Third, some children do not work regularly, often stay up late, causing biological clock disorder, causing insomnia. Fourth, there are some children for a long time lack of exercise, or sleep environment is poor, or suffering from chronic diseases and pain and other factors, can cause insomnia, and cause sleep disorders.