Sacrificing sleep? Here’s what it will do to your health

Cross Platform Link: This feature is part of CNN Parallels, an interactive series exploring ways you can improve your health by making small changes to your daily habits.

We are one groggy, cranky, sleep-deprived population.

Depending on our age, we are supposed to get between seven and 10 hours of sleep each night.

But according to the US Centers for Disease Control and Prevention, a third of us get fewer than seven hours of sleep per night. In addition, 50 million to 70 million Americans suffer from sleep disorders such as sleep apnea, insomnia and restless leg syndrome, which can ruin a good night’s shuteye.

And we’re not alone. In bedrooms around the globe, men, women and children are tossing and turning. According to World Sleep Day statistics, sleep deprivation is threatening the health of up to 45% of the world’s population.

Risking life and money

Science has linked poor slumber with high blood pressure, a weakened immune system, weight gain, a lack of libido, mood swings, paranoia, depression and a higher risk of diabetes, stroke, cardiovascular disease, dementia and some cancers.

Car crashes, industrial disasters, and medical and occupational errors also increase as we tire, not to mention a decrease in work productivity and efficiency.

A study by RAND Europe found that the United States loses an estimated $411 billion each year from workers who sleep fewer than six hours a night. That’s about 2.28% of US gross domestic product. Japan comes next, with $138 billion, or 2.92% of GDP, followed by Germany ($60 billion; 1.56% of GDP) and the United Kingdom ($50 billion; 1.86% of GDP).

But guess what would happen if those same people added an hour of pillow time? The US could add $226.4 billion back to the economy, the study said, and Japan would recover $75.7 billion, while Germany and the UK would be blessed with an additional $34.1 and $29.9 billion.

Consequences on your body

Exactly how does a lack of sleep affect the body? There are the obvious signs: irritation, moodiness, dull reflexes and a fuzzy mind. As you can imagine, how those continue to affect us depends on whether the deprivation is short-lived or long-term and chronic.

Interactive: How much sleep do you get?

Weakened reflexes

Studies show that after 17 to 19 hours without sleep, you’ll be functioning as if you’ve been drinking enough to raise your blood alcohol concentration to 0.05%. Skip a full 20 to 25 hours of sleep, and you’ll soon be at 0.1% – well over the US legal driving limit of 0.08.

In other words, a lack of sleep for one night can impair your reflexes and decision-making to the same extent as being over the limit.

But sleeping less than the recommended amount on a regular basis can be almost as bad. A lab-based sleep study found that people who were sleeping fewer than six hours a night for two weeks – and who thought they were doing just fine – functioned as badly on cognitive and reflex tests as people who were deprived of sleep for two full nights.

This is evident in traffic statistics. The National Highway Traffic Safety Administration estimates that at least 100,000 accidents reported to US police are the result of drowsy driving. This results in an estimated 1,550 deaths, 71,000 injuries and $12.5 billion in monetary losses, according to the National Sleep Foundation.

An unfocused mind

While you sleep, your brain is busy. It’s preparing for the next day, sorting your experiences and making new pathways for learning.

To capture newly acquired information, absorb fresh skills and form key memories – as well as to retrieve them later – you need plenty of sleep time to let your brain do its work. A lack of sleep therefore impacts your ability to pay attention, learn new things, be creative, solve problems and make decisions.

A chronic lack of sleep is also closely tied to anxiety and depression, as the body struggles to cope with the stress of sleepiness.

Some studies have found a connection between sleep apnea, a disorder with which you actually stop breathing for up to a minute, and cognitive impairment, and insomnia has been associated with reduced brain size.

There’s even growing evidence that poor sleep early in life can lead to the development of the plaques and tangles that cause Alzheimer’s and other kinds of dementia.

A study published this month in the journal Brain found that healthy middle-age adults who slept badly for just one night produced an abundance of the protein beta amyloid, responsible for the plaques characteristic of Alzheimer’s. A week of disrupted sleep upped the amount of tau, another protein responsible for the tangles associated with Alzheimer’s, frontal lobe dementia and Lewy body disease.

If that’