People are told the ideal amount of sleep is seven or eight hours, a behavior pattern which has become less frequent nowadays.

On average, almost a quarter of people say they are “surviving” on five hours, or less, sleep every night, according to a poll of 2,500 American workers conducted by leading mattress review website Mattress Clarity.

According to the poll, it appears that getting this little sleep could be attributed to people’s employment and the wider economy since 57 percent of people surveyed who sleep less than five hours say that work stress leads them to experience a bad night’s sleep.

“It’s true we can survive on five hours of night’s sleep, but it’s also true we can survive on a sugar diet, a 80 hour work week or living in isolation – for a time. The human mind has evolved to make sacrifices and survive in periods of extreme danger thus it can get by on minimal resources, however, this isn’t healthy or sustainable in the long term and will result in adverse effects both psychologically and physically,” said psychologist, Robert Stewart. “Firstly, surviving on five hours of sleep a night will mean we spend less time in REM (rapid eye movement) which means we’re less likely to process all the stimuli from the day and feel rested the day after”.

Long hours at work are taking their toll on the quality, and the length, of people’s sleep. It can seem like people are always working, as there has been a rise in Americans having more than one job, in order to make ends meet. And even when workers are at home, they don’t switch off from it; the survey found that 42 percent of Americans check their work emails before going to bed at night. And if something’s gone wrong, or if people are worried about what’s going to happen the next day, it is likely to keep them awake.

Broken down by state, the study found that Nevada is where the highest number of people are surviving on five hours of sleep or less, with 43.8 percent of workers reporting sleeping less than five hours. The approximately 170,000 casino workers in Las Vegas may account for Nevada leading the low-sleep survival statistics nationwide.

And California workers are among the most sleepless people in America, with 31.9 percent surviving on little sleep each night, making them the sixth most sleepless in the nation.

The state doing where the least amount of people say they sleep five hours or less is Arkansas, with just 8.6 percent of responses giving such answer.

“We’re likely to find after nights of five hours sleep that our concentration begins to diminish, lower levels of attention will increase our cognitive load and we’ll find ourselves becoming more agitated and irritated with those around us,” Stewart added. “A rise in cortisol, our stress hormone, will follow and this will mean we store more fat, our blood pressure increases and we struggle to uptake serotonin and oxytocin, our long term feel good hormones.”