Nearly three quarters of us are getting less sleep than we were five years ago, a survey has found.
Sleep has many beneficial effects
The research, commissioned by Travel Inn, found 57% of us feel that lack of sleep affects our performance at least once a week.
Sleep deprivation has led to 30% falling asleep on public transport, and 13% at a business meeting.
Figures show UK full-time employees work longer than in other European countries.
Our usual working week is the highest in the European Union - 43.3 hours compared with an average of 39.3 hours across the rest of Europe.
Amongst full-time employees, a quarter of British men and a tenth of women usually work more than 48 hours a week.
The survey found that over half of us (54%) have fallen asleep in an inappropriate place as a result of lack of sleep.
Often, this is, at worst, just embarrassing. For instance, 29% of us have fallen asleep during a film or a play.
But more worryingly, 5% of those surveyed said they had fallen asleep while driving.
There is a big North-South divide, with 85% of people in the North saying they get less sleep than they did five years ago, compared with just 59 percent in the South.
Sleep expert Professor Chris Idzikowski said: "People are working longer, but we are still trying to maintain decent social lives, and what is getting squeezed out is sleep. We are getting less sleep than we really need.
"We should all be aware of our body's needs and of the potential effects of not getting sufficient sleep, such as poor performance at work and generally feeling unhappy.
"We are not designed to work 100% of the time. The body needs to replenish itself."
Professor Idzikowski said the consequences of trying to do without sleep were graphically illustrated by the loss of the Space Shuttle Challenger.
"That was mainly because people were working through the night, and were being browbeaten into making decisions."
Researchers from Pennsylvania State University found that missing sleep can affect hormone levels and generate harmful chemicals in the body.
They suggested that women may live longer on average than men because they are better sleepers.
Separate research has also suggested that sleep deprivation may even cause mental retardation. Even losing an hour's sleep a night may have noticeable effects on a child's mental performance.
Travel Inn is launching a campaign to encourage people to have an extra hour of sleep every night for a week to find out if it improves their performance and general happiness.