Cheng Jingyang sets his phone aside at midnight, closes his eyes, and waits to fall asleep. Nothing happens.

The 23-year-old student of Hangzhou Dianzi University who is finishing fieldwork in Beijing for his thesis, recently spent more than 1,000 yuan ($146) on a memory-foam "deep sleep pillow" recommended on social media. He had already cut out caffeine and set a screen curfew. None of it had worked.

"I know it probably won't fix anything," he said. "But I wanted to try at least."

His mind endlessly drifts, he said — first to his thesis, then to the job market, then to a comment a professor made weeks ago that he cannot stop replaying in his head.

"It's not that I'm not tired. My body is exhausted, but my brain won't stop. It's like a browser with 30 tabs open and you can't find which one is playing the sound," he said.

Cheng's restless nights are part of a national pattern that researchers say is slowly worsening. A new study by the Chinese Center for Disease Control and Prevention, drawing on a nationwide survey of more than 100,000 residents conducted in 2024, found that people age 15 and above now sleep an average of just 7.24 hours a night.

Two decades ago, similar surveys put that figure closer to 7.5 hours. The drop of roughly 15 minutes sounds small, but spread across a population of 1.4 billion, the researchers warn, it adds up to a substantial public health concern.

A closer look at the numbers tells a sharper story. On average, Chinese adults now lie awake for approximately half an hour before falling asleep — a figure that climbs further among younger respondents, who tend to go to bed later, take longer to drift off, and increasingly reach for products or pills to try and fall asleep.

For many young Chinese, the findings only confirm what they already know from their own bedtime restlessness. Sleep has become a struggle — and for a growing number, a medical condition.

A 2024 white paper published by the China Sleep Research Society, which surveyed more than 10,000 people, found that college students born after 2000 spent an average of eight hours a day on screens, with many not putting their phones down until well past midnight.