Editor's note: In this series, we ask PKU experts general questions about science and culture and formulate their answers into short articles that are both fun and informative.

Peking University, April 1, 2026: Do you have trouble sleeping? Don't worry, you are not alone. About one-third of the world's adult population has some sort of sleep disorder, according to WHO estimates. In today's world, where changes happen fast and device addiction is rampant, getting a good night's sleep is increasingly seen as a luxury to many, even though sleep occupies one-third of our lives. For this article, we interviewed Professor Han Fang, director of the (Respiratory) Sleep Medicine Department, Peking University People's Hospital, for some simple tips to beat insomnia.

Regulate your life
It is important to have a fixed sleep schedule every day, where adults should aim for a bedtime at around 10:30pm and children a little earlier. While the average sleep recommendation is seven to eight hours, rigid adherence isn't necessary—what matters is getting enough rest to feel restored the next day.

Moreover, Prof. Han stressed avoiding routinely staying up, citing modern-day students as an obvious example, as they are wont to snack, play with their phone, or even study late into the night, explaining that such habits can severely disrupt one's circadian rhythm, leading to worse sleep. 

He also underlined the necessity of limiting screen time before bed, as the blue light emitted from phones, tablets, or TV can block the production of melatonin, a natural hormone in your body that promotes sleep.

Be active
Consistent with popular belief, Prof. Han recommended exercising during the day as an effective way to boost sleep at night. And the optimal way is to do activities outdoors at around noon, when one can enjoy a robust exposure to sunlight, which plays an important role in synchronizing one's circadian clock with the external environment, according to him. On the other hand, doing strenuous activities at night, especially close to bedtime, can have the opposite effect and delay the onset of drowsiness.

Aside from exercise, it is also important to keep away from the bed during the day, especially when you don't feel drowsy. This helps strengthen mental association between bed and sleep, making it easier to feel sleepy when you approach your bed at night.

Does alcohol help?
It varies from person to person, Prof. Han emphasized. But he noted that though alcohol can make one feel sleepy initially, it can disrupt normal sleep patterns and lead to lighter and less restorative sleep after midnight. As a general rule of thumb, he recommended against the intake of alcohol and caffeine at night.

What if it gets serious?
If the insomniac condition is chronic—occurring at least three times a week for more than three months—or if it leads to bad mood, poor focus, or drowsiness the next day, with self-intervention having proved ineffective, then it's time to seek medical help. 

Cognitive Behavioral Therapy (CBT) should be the first option for remedy, with medication acting as a fallback. According to Prof. Han, newer sleeping aids generally carry lower risks of dependency compared to older medications. Thus, a short course of sleeping medication under a doctor's instructions can be way less harmful than toughing it out.

Written by: Chen Shizhuo
Edited by: Zhang Jiang
Interview done by: Chen Shizhuo, Guo Yasong, Huang Zhen, Mao Jingping
Source: PKU WeChat (Chinese)