1. There’s a part of your brain that regulates your circadian rhythms with the help of light.
It’s a bit like a master clock for your body, and it’s called the “suprachiasmatic nucleus”. It lives just above part of your brain called the optic chiasma and receives input from your eyes about the amount of light in the outside world.
2. Blind people often have trouble with sleep because daylight is so important to regulating circadian rhythms.
About half of all blind people who have no light perception at all suffer from non-24-hour sleep-wake disorder, where their internal clock doesn’t match up with the day and night cycle.
8. The amount of sleep different animals need varies wildly.
Giraffes need an average of 1.9 hours, but cats need more than 12 hours a day.
10. No matter how much you try, you won’t be able to dramatically alter your internal clock.
12. Half of all teenagers may be sleep deprived.
Small children are early birds, but during adolescence people tend to become later risers. Half of all teenagers may be sleep deprived, thanks in part to early school start times.
13. The record for the longest period without sleep is 11 days.
It was set by Randy Gardner in 1965. Others have claimed that they’ve gone without sleep for longer, but Guinness World Records no longer keeps records of voluntary sleep deprivation attempts due to associated health risks.
20. Sleep disruption caused by working nights is even classified as a potential cause of cancer by the World Health Organisation.
Shift work involving disruption of normal sleep routines is currently classified as an “IARC 2A carcinogen”. Studies have shown that long-term night workers have a higher risk of breast cancer than women who don’t work at night.
21. Sadly, you can’t escape sleep problems by escaping Earth.
Going to space would probably make everything a whole lot worse. Without a natural day/night cycle, astronauts’ internal clocks could start to get out of sync. On a 17-month simulated Mars mission, four out of six of the crew members had sleep problems.
22. But there’s some good news! You can catch up on lost sleep.
But there’s no shortcut to repaying your sleep debt. It’s a case of sleeping those extra hours that you missed. If you miss one hour a night for a year, that’s over two weeks you’ll have to catch up on. Better get started.