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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 on your physical health?

One in 3 of us suffers from poor sleep, with stress, computers and taking work home often blamed.

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 8 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 due to bad sleeping habits.

Find out the common medical causes of fatigue.

What happens if I don't sleep?

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 fall asleep during the day. Your risk of injury and accidents at home, work and on the road also 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 7 ways in which a good night's sleep can boost your health:

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.

Sleep can slim you

Sleeping less may mean you put on weight! Studies have shown that people who sleep less than 7 hours a day tend to gain more weight and have a higher risk of becoming obese than those who get 7 hours of slumber.


Sleep boosts mental wellbeing


When people with anxiety or depression were surveyed to calculate their sleeping habits, it turned out that most of them slept for less than 6 hours a night.

Sleep prevents diabetes

Studies have suggested that people who usually sleep less than 5 hours a night have an increased risk of developing diabetes.

It seems that missing out on deep sleep may lead to type 2 diabetes by changing the way the body processes glucose, which the body uses for energy.

Sleep increases sex drive



Sleep wards off heart disease


Sleep increases fertility


How to catch up on lost sleep





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 about some common energy stealers.

Tips for getting a good night's sleep.

Page last reviewed: 30 May 2018
Next review due: 30 May 2021