One in every four stressed Americans suffers from insomnia, a new study has found adding that women are the most affected.
The study on more than 9,000 adults found that one in three person wakes up in the middle of the night at least three times a week.
It showed that 27 per cent of women wake up every night, compared to 19 per cent of men following financial fears, family arguments or problems at work.
Lead researcher Dr Maurice Ohayon, of California's Stanford university, describes the findings as "incredible".
"In terms of comparing how common it is with other sleep problems, there is no comparison. This is off the scale," Daily Express quoted him as saying.
Many people only suffer insomnia for a few weeks, but as their stress goes away, so does the sleep disorder.
However, for people with chronic insomnia, the problem can go on for a long time, leading to huge distress, personal problems and illness.
"This is the first really good data we have showing the importance of nocturnal awakening in insomnia," said Dr James Walsh, of St Luke's hospital, in St Louis, Missouri,
"It shows a strong overlap between the awakening and other sleep problems and it suggests that nocturnal awakening is a very under-appreciated aspect of insomnia," he added.