Sleeplessness refers to the circumstances when one wants to sleep but can't fall asleep or often wakes up, has a poor quality of sleep, sleeps for less than six hours or doesn't feel refreshed in the morning. This can result in dysfunction in daytime activities, tiredness or general malaise.

Wang Yuping, neurology director of Beijing's Xuanwu Hospital, said that if a person features one of the above four characteristics, with daytime dysfunction, he/she can be diagnosed as suffering from sleeplessness.

Sanofi China, jointly with QQ-health, recently released a survey on the sleeplessness of Chinese people, showing that among 8,000 people in 362 Chinese cities, 80 percent are experiencing or have experienced sleeplessness. A total of 66.77 percent of them can't fall asleep within 30 minutes.

According to the survey, 87.76 percent of participants in Shanghai have experienced sleeplessness, the highest in China.

The following are the top five sleepless cities in China.

   Shenzhen, Guangdong Province

Shenzhen, Guangdong Province

People who have experienced sleeplessness: 76 percent