Not getting enough sleep is an increasingly common problem across the globe. While people have differing sleep needs in regards to how much sleep is enough for them, in general the average adult needs 7 to 8 hours of sleep a night. There are 2 stages or cycles of sleep:

Rapid Eye Movement (REM) sleep makes up about 25% of the total sleep time and typically is broken up into 4 or 5 individual segments. During REM sleep the body is the most relaxed and dreaming takes place.

Non Rapid Eye Movement (Non REM) sleep makes up about 75% of the total sleep time and is normally without dreams occurring. This is when limb movement occurs during the sleep and also when sleep walking may take place.


During a normal sleep cycle, there will be movement between the 2 stages with the amount of REM sleep increasing as the night progresses.

The Need For Sleep

  • The importance of sleep is still a major research subject, but it has been established that sleep is:
  • When the body heals and restores itself.
  • When the production of important hormones increases.
  • Critical to the maintenance of proper brain functioning, memory and problem solving skills.
  • What reduces the risk of accidental injury caused by a lack of alertness.
  • Important to the overall health and wellbeing.

How Much Sleep?

  • The typical human sleep requirements are:
  • Newborns – 18 hours in a 24 hour cycle
  • Ages 3 to 5 – 11 to 13 hours of sleep a night
  • Ages 6 to 11 – 9 to 13 hours of sleep a night
  • Pre-teenagers – 9 to 11 hours of sleep a night
  • Teenagers – 9 to 10 hours of sleep a night
  • Adults – 7 to 8 hours of sleep a night
  • The need for sleep is age related. That does not only mean that the number of hours of sleep reduces, it also means that the sleep is less deep.
  • The body has a built in time keeper called the Circadian clock. This is due to the production of chemicals by the body that affects energy levels and sleepiness. Daylight also affects the body clock and a drop in daylight causes the increased production of a hormone called melatonin which helps in regulating the sleeping and waking cycle.


Research shows that around 25 to 40% of women across the world need more sleep than they get. It also shows that 15 to 30% of men suffer from sleep disorders.

Sleep Disorders

  • Sleeping disorders can take various forms which include:
  • Bruxism (teeth grinding while asleep)
  • Delayed Sleep Phase syndrome (as in the case of those who work the nigh shift or keep changing their sleep times)
  • Sleep Apnea (breathing stops momentarily while asleep)
  • Narcolepsy (excessive daytime sleep)
  • Parasomnias (sleep walking, night terrors, periodic limb movement disorders, acting out violent dreams, compulsion to move your legs)

Also Read: Do you have a sleep disorder?

Lack Of Sleep – What Happens

  • Lack of sleep can result in a wide range of physical and mental problems. The most common of these are:
  • Altered body functioning
  • Paleness of the skin and dark circles under the eyes
  • Reduced memory, concentration
  • Increased reaction time
  • Headaches
  • Irritability
  • Blurred vision
  • Slurred speech
  • Digestive problems such as nausea, loss of appetite, constipation, weight loss or gain
  • Physiological changes leading to dizziness, fainting, tremors, increased blood pressure
  • Increased risk of cardiovascular conditions and type 2 diabetes
  • Psychiatric and neurological problems like depression, alcoholism, a feeling of detachment, hyperactivity, bi-polar disorder, types of psychosis like hallucinations, delusions, disorganized thinking

Physical Causes of Insomnia

  • There are a number of physical issues that can lead to insomnia. Among the most common are:
  • Consumption of caffeine which is found in tea, coffee, cocoa and aerated drinks
  • Consumption of alcohol which, while making a person sleepy initially, will have an adverse effect on sleep quality and duration
  • Consumption of sugar before sleeping may cause a drop in sugar levels at night, affecting sleep quality
  • Low magnesium levels can cause disturbed sleep. Magnesium rich foods include mustard, green leafy vegetables, nuts, seeds, pulses, beans, bananas, avocados, garlic, prunes and dates. Adding these to your diet may help in dealing with sleeplessness
  • Hyperthyroidism- excess secretion of thyroid hormone by the thyroid glands speeds up the vital functions of the body thereby creating restlessness
  • Menstruation, pregnancy and menopause which can result in low estrogen levels before menstruation cycle causing temporary sleeplessness; high levels of estrogen and progesterone during pregnancy may lead to longer REM sleep; a drop in estrogen levels during menopause may result in hot flushes and disturbed sleep
  • Restless leg syndrome which is when there is a feeling of burning, itching or tickling in the legs which is more pronounced at night
  • Neurological conditions like Parkinsonism, Alzheimer’s disease, dementia, traumatic brain injury
  • Other health issues

Also Read: Excessive Daytime Sleepiness, is it something to worry about?

Psychological Causes Of Insomnia

  • A number of psychological causes can be associated with insomnia. These include:
  • Stress of various kinds. Short term stress caused by an upcoming event such as an examination; medium term due to something like bereavement, a birth in the family etc.; and sleep related stress where the sleeplessness starts a cycle in which the lack of sleep makes getting to sleep difficult
  • Depression
  • Anxiety
  • Dementia
  • Bipolar disorders
  • Post-Traumatic Stress Disorder (PTSD)
  • Schizophrenia
  • Obsessive Compulsive Disorder (OCD)

Lifestyle Causes Of Insomnia

  • The lifestyle factors that affect sleep are large in number. The most common are:
  • An irregular sleep schedule.
  • Inadequate exercise or physical activity.
  • Excessive stimulation (both mental and physical) before sleeping.
  • Too much noise or light to allow for failing asleep.
  • Age related lifestyle changes.

Relaxation And Sleep

Relaxation is key to good sleep and can improve overall health and the feeling of well-being. All it usually takes is just 15 minutes a day devoted to relaxing and unwinding. Progressive deep muscle relaxation, massage, yoga, meditation and hypnotherapy are few of the relaxation techniques that can be practiced easily to prevent or to manage sleeplessness effectively.

Remember, sometimes the most productive thing one can do is to sleep.

Article by Ms. Mahalakshmi.S.
Consultant Psychologist
Kauvery Hospital, Chennai