Fierce competition

Tang Muming, a data analyst from Suzhou, Jiangsu province, began having sleep problems when she was studying for her master's in the United States a year and a half ago.

She often goes to sleep at 2 am because of the pressure she feels, and one or two days a week she falls asleep around 4 am.

"I even counted sheep sometimes, but it didn't work at all," she said.

Tang, 25, used to study overnight with her classmates in the library. "There was a week when my daily sleep time was just three hours," she said. "I was exhausted then."

Before she was offered her present job, Tang endured a long period of anxiety as her friends fielded offers before she did. The fierce competition in the data analysis field has added to her anxieties.

"We can be easily replaced by new people," she said. "Our jobs require us to keep updating our knowledge of big data, business analysis and artificial intelligence, since everything changes so fast."

Han said sleep problems were not confined to college students and those in the work force, with primary and secondary school students also affected due to heavy workloads and fierce competition.

Many young adults often ignore sleep problems and have irregular lifestyles or attended too many social activities.

"They think it is fine to overdraw (their energy balance) a bit at a young age, but in the long run, their situation will be totally changed," Han said.

People younger than 25 should not have sleep problems, Guo said, but the number of patients in that age group had increased considerably during the past five years. "Some are teenagers," he said.

Most people 20 to 40 years old do not sleep until after midnight, which has affected their normal biological clock and resulted in declining sleep quality, short sleep duration and even loss of sleep, Guo said.

He said that ideally, an adult should get to sleep at around 10 pm and sleep for seven to eight hours.

Almost all his elderly patients developed bad sleep habits or sleep problems when they were young, Guo said.