So, God caused the man to fall into a deep sleep. While the man slept, the Lord God took out one of the man’s ribs and closed up the opening. Genesis 2:21.

Image from Ben Blennerhasset at Unsplash

Sleep is an ACTIVE process that involves intersecting psychological and physiological aspects. It is a state of unconsciousness in which the brain is relatively more responsive to internal than external stimuli. It is associated with rest and crucial to health and wellbeing.

Stages of Sleep[i]

1. Non-REM (Rapid eye movement) sleep

  • A stronger stimulus is needed to wake with each progressive stage.
  • Alternates with REM sleep throughout the night.
  • Difficult to rouse as this stage progresses.

2. REM (Rapid eye movement sleep) sleep

  • Episodic rapid eye movement.
  • No muscle movement.
  • This stage is when dreaming happens.

Stage N1 is considered a transition between wake and sleep. It occurs upon falling asleep and during brief arousal periods within sleep and usually accounts for 2–5% of total sleep time.

Stage N2 occurs throughout the sleep period and represents 45–55% of total sleep time.

Stage N3 (slow-wave sleep) occurs mostly in the first third of the night and constitutes 10–20% of total sleep time. This is the period of deep refreshing sleep.

REM represents 20–25% of total sleep time and occurs in 4–5 episodes throughout the night. [ii]

There is no fixed number of hours of sleep, it varies from person to person. Some studies report 3–5 hours of sleep for normal body function, others report 7- 8 hours. However, there are recommended hours of sleep per age group.

What is the normal sleep cycle?

The sleep cycle begins when you fall asleep. Waking usually transitions into light NREM sleep. NREM sleep typically begins in the lighter stages (N1 and N2) and progressively deepens to slow-wave sleep as evidenced by higher-voltage delta waves on an electroencephalogram( EEG). When delta waves account for more than 20% of the sleep EEG, the sleep stage is considered to be stage N3.[iii]

REM sleep follows NREM sleep and occurs 4–5 times during a normal 8-hour sleep period. The REM period becomes progressively longer through the night where the first REM period of the night may be less than 10 minutes in duration, while the last may exceed 60 minutes. The NREM–REM cycles vary in length from 70 to 100 minutes initially to 90 to120 minutes later in the night.[iv]

Image from Verywell mind


Insomnia is a syndrome defined as difficulty with initiation, maintenance, duration or subjective quality of sleep that is severe enough to result in impairment of daytime functioning, occurring at least three times per week, and over a duration of at least one month. [vi]

It is difficulty falling asleep or staying asleep even when a person has the opportunity and an enabling environment.


  • 20–40% of adults from different countries complain about difficulty sleeping at some point each year.
  • It is inconstant: varies based on criteria used.
  • A common reason for patient visits.
  • Increases with increasing age: the elderly are the most affected.


Based on the cause:

  • Secondary insomnia: Due to a medical, psychiatric or environmental cause. This is the most common type.

Based on duration:

  • Chronic Insomnia: Disrupted sleep occurring at least three nights per week, lasting at least three months.

Causes of Secondary insomnia

1. Medical conditions: Mainly those that cause pain. Congestive Heart failure, Neurodegenerative diseases Stroke, Asthma, COPD, etc.

2. Psychiatric disorders: Mood disorders like Bipolar affective disorder and depression.

3. Environmental causes: Noise, life-threatening events, change in the work environment, use and abuse of stimulants (e.g. caffeine, cocaine, amphetamine), alcohol addiction or its withdrawal and opioids.


  • Difficulty initiating sleep (Initial insomnia)
  • Difficulty maintaining sleep (middle insomnia)
  • Waking up earlier than needed (terminal insomnia)
  • Decreased total hours of sleep
  • Reduced productivity or well-being.
  • Excessive daytime sleepiness (hypersomnia)


  • Slowed reaction time
  • Poor concentration
  • Drowsiness
  • Disturbed coordination


· Headaches

· Irritability

· Anxiety

· Reduced quality of life


Non-drug treatment

The primary goals of treatment are “to improve sleep quality and quantity, improve related daytime impairments by enhancing daytime function, reduce sleep latency and wakefulness after sleep onset, and increase total sleep time.” [vii]

1. Patient Education (Improve Sleep habits)

  • Outside of sleep, avoid activities in bed such as watching television or reading.
Image from Nubelson Fernández at Unsplash
  • Avoid heavy meals before bed.
  • Avoid activities that get you stimulated and upset late in the day.
  • Practice daily relaxation techniques at least 20 minutes before bedtime - Repetitive prayers, mindfulness meditation, breath focus.
  • Exercise early in the day before dinner to alleviate stress, not close to bedtime.
  • Maintain a regular schedule for bedtime and wakening; avoid naps.
  • Don’t watch clock or count sheep while in bed, get out of bed and spend quiet time until sleep comes.
  • Maintain comfortable bedroom temperature while minimising light and noise.[v]

2. Cognitive Behavioural therapy

This is effective especially in cases of primary insomnia. A combination of cognitive-behavioral therapy and pharmacological treatment approaches are more effective in the treatment of chronic insomnia. Elements include but are not limited to Sleep hygiene education, cognitive therapy and relaxation therapy. [v]

Drug treatment

Image from Kelly Sikkema at Unsplash


[i] 600L Group A (2019) Medical Students Lectures: Coma, Sleep, Epilepsy, Stroke, Spinal Cord Lesions Higher Cerebral Function notes for revision pre‐dementia lecture

[ii]Kryger MH, Roth T, Dement WC, W Lowell, Berry JQ. Principals and Practice of Sleep Medicine. 6th Edition. Philadelphia, Pa: Elsevier; 2017.

[iii] Berry RB, Albertario CL, Harding SM, et al. The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications. Version 2.5. Darien, IL: American Academy of Sleep Medicine; 2018.

[iv] Kryger MH, Roth T, Dement WC, W Lowell, Berry JQ. Principals and Practice of Sleep Medicine. 6th Edition. Philadelphia, Pa: Elsevier; 2017.

[v] Medscape





Medical doctor. Creative writer. I write about stories, writing, health and wellness.

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Chinaza Ebere Eziaghighala

Medical doctor. Creative writer. I write about stories, writing, health and wellness.