Why lack of sleep is bad for your health

Many effects of a lack of sleep, such as feeling grumpy and not working at your best, are well known. But did you know that sleep deprivation can also have profound consequences for your physical health?

When you might need more sleep than normal

There are some situations when you'll need more than the standard eight hours of sleep a night. It’s not unusual to want 10-15 hours of rest and sleep a day if you are:

  • recovering from illness
  • pregnant
  • living with a chronic illness
  • have been through extreme physical exertion, such as running a marathon

One in three Britons suffers from poor sleep, with stress, computers and taking work home often blamed for the lack of quality slumber.

However, the cost of all those sleepless nights is more than just bad moods and a lack of focus.

Regular poor sleep puts you at risk of serious medical conditions including obesity, heart disease and diabetes – and it shortens your life expectancy.

It’s now clear that a solid night’s sleep is essential for a long and healthy life.

How much sleep do we need?

Most of us need around eight hours of good quality sleep a night to function properly – but some need more and some less. What matters is that you find out how much sleep you need and then try to achieve it.

As a general rule, if you wake up tired and spend the day longing for a chance to have a nap, it’s likely that you’re not getting enough sleep.

A variety of factors can cause poor sleep, including health conditions such as sleep apnoea. But in most cases it’s a matter of bad sleeping habits.

Find out the common medical causes of fatigue.

What happens if I don't sleep?

Oversleeping

Although it isn’t as common as not getting enough sleep, sleeping too much can also cause problems.

Oversleeping has been linked to physical problems such as diabetes and heart disease.

According to the Mental Health Foundation, oversleeping can occur in 15-40% of people with depression.

Everyone’s experienced the fatigue, short temper and lack of focus that often follow a poor night’s sleep.

An occasional night without sleep makes you feel tired and irritable the next day, but it won’t harm your health.

After several sleepless nights, the mental effects become more serious. Your brain will fog, making it difficult to concentrate and make decisions. You’ll start to feel down, and may drop off during the day. Your risk of injury and accidents at home, work and on the road increases.

Find out how to tell if you’re too tired to drive.

If it continues, lack of sleep can affect your overall health and make you prone to serious medical conditions such as obesity, heart disease, high blood pressure and diabetes.

Here are seven ways in which a good night's sleep can boost your health:

1. Sleep boosts immunity

If you seem to catch every cold and flu that’s going around, your bedtime could be to blame. Prolonged lack of sleep can disrupt your immune system, so you’re less able to fend off bugs.

2. Sleep can slim you down

Sleeping less can make you weigh more! Studies have shown that people who sleep less than seven hours a day are 30% more likely to be obese than those who get nine hours of sleep or more.

It’s believed to be because sleep-deprived people have reduced levels of leptin, the chemical that makes you feel full and increased levels of ghrelin, the hunger-stimulating hormone.

3. Sleep boosts your mental wellbeing

Given that a single sleepless night can make you irritable and moody the following day, it’s not surprising that chronic sleep debt may lead to long-term mood disorders like depression and anxiety.

When people with anxiety or depression were surveyed to calculate their sleeping habits, it turned out that most of them slept for less than six hours a night.

4. Sleep prevents diabetes

Studies have suggested that people who usually sleep less than five hours a night have an increased risk of having or developing diabetes.

It seems that missing out on deep sleep may lead to type 2 diabetes by changing the way the body processes glucose, the high-energy carbohydrate that cells use for fuel.

5. Sleep increases your sex drive

Men and women who don’t get enough quality sleep have lower libidos and less of an interest in having sex, research shows.

Men who suffer from sleep apnoea – a disorder in which breathing difficulties lead to interrupted sleep – also tend to have lower testosterone levels, which can lower libido.

6. Sleep wards off heart disease

Long-standing sleep deprivation seems to be associated with increased heart rate, an increase in blood pressure and higher levels of certain chemicals linked with inflammation, which may put extra strain on your heart.

7. Sleep increases your fertility

Difficulty conceiving a baby has been claimed as one of the effects of sleep deprivation – in both men and women. Apparently, regular sleep disruptions can impair fertility by reducing the secretion of reproductive hormones.

How to catch up on lost sleep

If you don’t get enough sleep, there’s only one way to compensate – getting more sleep.

It won’t happen with a single early night. If you’ve had months of restricted sleep, you’ll have built up a significant sleep debt, so expect recovery to take several weeks.

Starting on a weekend, try to tack on an extra hour or two of sleep a night. The way to do this is to go to bed when you’re tired, and allow your body to wake you in the morning (no alarm clocks allowed!).

Expect to sleep for upwards of 10 hours a night, at first. After a while, the amount of time you sleep will gradually decrease to a normal level.

Don’t rely on caffeine or energy drinks as a short term pick-me-up. They may boost your energy and concentration temporarily, but can disrupt your sleep patterns even further in the long term.

Read these common energy booster myths.

Read practical tips for getting a good night’s sleep.

Read articles on ways to beat insomnia.

Get help for your sleep problem

Think you might have a sleep problem?

Try one of these NHS-reviewed sleep apps aimed at getting you to sleep well.

Page last reviewed: 18/06/2013

Next review due: 18/06/2015

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The 2 comments posted are personal views. Any information they give has not been checked and may not be accurate.

gurdeep84 said on 02 March 2014

Having sleepless/poor sleep nights for last one year due to my baby.. He still wakes up 2-3 times at night and does not Settle down on his own. At day time I try to finish household work when he takes nap... What to do in this case? :)

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alpineangel said on 31 August 2013

If I am suffering from insomnia how can I possibly hope to sleep for 10 hours!! I'm lucky if I manage 3 hours at the moment.

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