What causes serious lack of sleep? How many people are affected? How can lack of sleep affect our health? What can we do about it?

Why do we sleep?

Sleep is an active period in our lives. Scientists still don’t understand exactly how it happens, but it is clear that sleep is essential. During this time, we solidify and consolidate memories, by transferring pieces of information from short-term memory to long-term memory. Also, it is during sleep that our muscles grow, tissues are being repaired and we synthesize hormones.

Two main hormones that regulate sleep are cortisol and melatonin. Levels of cortisol should be high in the morning, when we wake up, whereas melatonin is secreted in the evening, when our optic nerves detect natural light diminishing.

What causes sleep deprivation?

There are four main causes i.e.

  • A temporary change in our situation - like jet lag while travelling or a move to shift work or stress the night before an exam.
  • Psychological reasons - anxiety, depression, long term stress, schizophrenia and bipolar disorder can all make it harder to sleep.
  • Physiological reasons – like pain due to accident or illness, degenerative diseases like Alzheimer’s or changes in our natural body clock as we get older.
  • Medication – for instance the ingredients in some over the counter remedies for colds, flu and asthma inhibit sleep.

Some women during menstruation and most women during menopause have trouble sleeping. The reason for this are changes in levels of oestrogen and progesterone. Certain supplements can help women cope with these issues.

How many people have problems sleeping?

The NHS advises that about a third of people in the UK have episodes of insomnia. And that it tends to be more common in women and more likely to occur with age.

This may be partly due to a steady decline in the amount of deep sleep we experience as we grow older.

How can lack of sleep affect our health?

We know that lack of sleep can make us feel tired and irritable. However, it can also have more serious health effects.

Sleep fuels the body and in particular our immune system. So it is not surprising that lack of sleep could convert health to illness if it persists.

The NHS advises that lack of sleep increases your risk of:

  • Colds and flu (By weakening your immune system)
  • Obesity and Diabetes
  • Heart Disease
  • Anxiety and Depression
  • Infertility

Lack of sleep very quickly makes it harder to remember as well as harder to function effectively at work. For example sleep deprivation increases the risk of accidents.

Conversely the idea of 'sleeping on' an idea seems to have a scientific basis, with sleep helping consolidate our memories.

NB Some studies suggest that both too little and too much sleep could be bad for our health. A systematic review from 2018 showed that sleeping more than 7-8 hours per night can have worse consequences in terms of cardiovascular health, than not getting enough sleep.

What can we do to get a good night’s sleep?

The Sleep Council provides ten tips. These include:

  • Keeping regular hours
  • A room temperature of 16 – 18 C
  • Taking more exercise – but not close to bedtime
  • Dealing with worries by making a list of things to do the next day

However, sometimes we may need to tackle the underlying causes - which might be due to physical illness or medication, psychological problems or changes in our natural body clock.

For instance if sleep problems are due to changes in our body clock as we get older, then we need to help reset our body clock. We can do this by getting exposure to bright light during the day, then avoiding ‘blue light’ (from computers, tablets and mobile phones) before we go to bed and avoiding background lights while in bed at night.

If your sleep problems are stress related the NHS recommends keeping a diary to help you identify what triggers your stress, considering one of their suggested 10 stress busters or getting support through a stress management group or class.

Relaxation techniques are also recommended – including yoga, mindfulness, listening to relaxing music or a warm bath. In more serious cases of insomnia Cognitive Behavioural Therapy (CBT) can also help break the cycle of insomnia. This can also help where pain is what is preventing sleep.


  • Sleep deprivation can be due to temporary problems (like jet lag, pre exam stress or taking cold and flu remedies containing caffeine).
  • However, the causes may be more deep seated – and either mental (like longer term anxiety, stress or depression) or physical (like pain due to illness or changes to our body clock as we get older).
  • About a third of people in the UK are estimated to experience episodes of insomnia.
  • If it persists this can affect our health, including increasing the risk of colds, flu, obesity, diabetes and heart disease.
  • To get a good night’s sleep we need to ensure we’re in a conducive environment (not too noisy, hot or cold), to address the causes of insomnia (from medical help to address pain or depression - to using light and darkness at the right times to reset our body clock) and/or use one of the range of relaxation techniques (from yoga to a warm bath).

Reviewed and updated by Sara Radenovic May 2019, next update April 2023