Insomnia – Definition, Types, Symptoms and Diagnosis

In easy words, insomnia is typically defined as the inability to sleep. The word insomnia itself comes Insomnia - Definition, Types, Symptoms and Diagnosis from the Latin word “in somus” which means no sleep. Insomnia or inability to sleep is mainly specified by difficulty in initiating sleep, frequent awakenings, and difficulty in returning to sleep.

From a condition, it becomes a disorder when the patient has a daytime impairment.1 Insomnia is a common complaint in medical practice and a rising concern for public health. Initially considered as a symptom, insomnia is now defined as a disorder and classified separately in the Diagnostic and Statistical Manual of Mental Disorders-5th edition (DSM-V) and International Classification of Sleep Disorders- 3rd edition (ICSD-3).2 This article mainly focuses on understanding insomnia, its types, reasons, signs, and symptoms, non-pharmacological and pharmacological methods for the management of insomnia.

How common is it?

The prevalence of insomnia depends upon the criteria used to define and diagnose and on the population under study. Insomnia is fairly a common disorder with one-third of people in the United States presented by one or the other symptom.1 Approximately 6% of the total population meet the diagnostic criteria for insomnia.3 Studies have reported that approximately 9 to 15 % of the adults complain of chronic insomnia, whereas occasional insomnia is presented by 27% of the adults. Among the general population, the higher rates are observed in females as compared to men, separated or divorced individuals, those with loss of loved ones, and older people.2

Types of insomnia

Insomnia is commonly classified into acute and chronic, based on duration and pattern of sleep during Insomnia - Definition, Types, Symptoms and Diagnosis the night. According to the International Classification of Sleep Disorders- 3rd edition (ICSD-3), insomnia is classified as:4

Acute or transient insomnia:

Acute or transient insomnia is presented with insomnia for short durations and caused due stress, new medication, travel across time zones, or as a new symptom to an underlying disorder. Sleep disturbances experienced in acute insomnia patients are generally within three months.

Chronic Insomnia: 

Chronic or persistent insomnia develops when acute insomnia occurs and becomes perpetuated, or insomnia that may be longstanding without a clear episode or time of onset. It is usually a multifactorial disease affected by psychological, physical, and behavioral factors. In chronic forms of insomnia, sleep disturbances are experienced by patients for the last three months for at least three times a week at the night time.

Other Insomnia Disorder: Sleep difficulties that do not meet the diagnostic criteria for either short-term or chronic insomnia disorders.

How is it diagnosed?

A detailed sleep history with proper sleep logs is the key to evaluate insomnia. While confirming the diagnosis of insomnia, a clinician should be able to differentiate and rule out other sleep-related disorders such as restless leg syndrome, sleep apnea, periodic limb movements that may lead to insomnia as a secondary problem. The diagnosis of insomnia is usually concluded by the night time Insomnia - Definition, Types, Symptoms and Diagnosis routine of the patient. In rare case scenarios, a sleep study is required. The following methods are generally used to evaluate the severity and diagnose insomnia.

Laboratory tests: The laboratory tests provide supportive evidence to evaluate the underlying medical conditions that can be associated with insomnia. The initial laboratory workup should include tests for thyroid functioning, complete blood picture, serum iron levels, liver function test, kidney function tests, and blood sugar levels.5

Surveys or questionnaires: Questionnaires, self-assessment forms, and various assessment scales help to keep a record of sleep timings, disturbances, and quality of sleep. The most commonly recommended scales for patient self-evaluation are Epworth Sleepiness Scale having a score from 0 to 24, of more than 15 indicating severe daytime sleepiness, and Pittsburgh Sleep Quality Index, indicating poor sleep scale of greater than 5.5

Sleep logs/ nighttime diary: The most cost-effective and easy method of assessing the sleep-wake cycle in an individual is to keep sleep logs or using diaries. The sleep logs should be maintained for at least 2-4 weeks also including the documentation of consumption of alcohol and caffeine, bedtime activities, and record of daytime napping. Sleep logs are used to evaluate the total sleep time (TST), episodes of wakefulness after sleep onset (WASO), sleep efficiency (SE), and circadian rhythm disturbances. The only limitation with the method of keeping sleep logs is the reliability and validity of its documentation.5 Insomnia - Definition, Types, Symptoms and Diagnosis

Actigraphy: Actigraph is a non-invasive device worn on the wrist used to record the gross motor activities during the daytime and sleep. The various parameters monitored by Actigraphy are total sleep duration, wakefulness after sleep onset, sleep latency, and daytime naps. The one shortcoming associated with this device is that it cannot record the periodic limb movements (PLM) or abnormal breathing patterns during insomnia.5

Polysomnography: Polysomnography is considered as the most preferred method in the diagnosis of various sleep disorders. This includes sleep-apnea, sleep-related hypoventilation, and parasomnias. It is not indicated for initial assessment of primary insomnia unless a co-existing sleep disorder is suspected.5

To confirm the diagnosis of insomnia, one of the following form of daytime impairment

must occur despite the adequate opportunity and environment for sleep:6

– Fatigue/malaise

– Difficulty to concentrate or memory impairment

– Social or vocational dysfunction

– Mood disturbance or irritability Insomnia - Definition, Types, Symptoms and Diagnosis

– Daytime sleepiness

– Motivation/ energy reduction

– Proneness to dangers or accidents

– Headaches and gastric problems

– Concerns and continuous worries about the sleep

Causes of insomnia

There are mainly three types of contributing factors that have been linked to insomnia: predisposing, precipitating, and perpetuating. All these factors play an important role at different points in the course of insomnia. For example, several psychological, physiological, and hereditary factors have been postulated to predispose to insomnia. Other risk factors such as psychological and physical dysfunctions, environmental, family, and work-related factors have been categorized as precipitating factors that are linked indirectly to the onset of insomnia. Maladaptive sleep habits, poor sleep hygiene, and behavioral attitudes about sleep have been associated with the perpetuation of insomnia.7

Although insomnia can affect any age group, women and the elderly (>65 years) are more susceptible as compared to men and younger populations. Stress is considered as the most common psychological Insomnia - Definition, Types, Symptoms and Diagnosis factor that can lead to sleep disturbances. In children, developmental issues, hyperactive behaviors, separation anxiety can increase the risk of sleep problems. Certain behavioral factors such as excessive worrying, alcohol, or substance abuse/dependence, excessive caffeine intake, and excessive smoking can also potentially affect the sleep-wake cycle. Some comorbidities like depression, mood disorders, post-traumatic stress disorder, sleep apnea, heart problems, hypertension, diabetes mellitus, gastrointestinal reflux, and respiratory problems can also increase the risk of insomnia.2

Signs and symptoms:2

The sleep disturbances in patients of insomnia are generally manifested as:

– Difficulty in falling asleep (Sleep Onset Insomnia),

– Maintaining the continuity of sleep for an adequate amount of time at night

– Episodes of awakening in between the sleep and difficulty in falling asleep again.

– Waking up too early before the desired time irrespective of the adequate environment for sleep (Early Morning Insomnia)

– Significantly impairing the daytime functioning

– Tiredness in the morning

– Decreased productivity at work

– Increased chances of accidents and errors Insomnia - Definition, Types, Symptoms and Diagnosis

– Difficulty to concentrate

– Increased frequency and duration of day time napping

– Poor quality of life

– In children, insomnia is usually reported as frequent episodes of night awakening followed by resistance in going back to bed

– Development of anxiety and fear due to disturbed sleep

– Inability to concentrate and behavior problems

Treatment of insomnia:

Non-pharmacological management:

Sleep hygiene: Creating a peaceful and comfortable environment for sleep is the first step towards the treatment of insomnia. This includes creating an environment conducive to sleep, maintaining a schedule i.e. going to bed and waking up around the same time every day. Don’t stay awake in bed, if you cannot sleep get up and do some activity. Avoid intake of alcohol or caffeine in the late evenings or just before bedtime. Create a cool, calm, dark, and ambient environment for comfortable sleep with minimal distractions.8

Sleep restriction therapy: This method helps in improving the efficiency of sleep with an increase in the percentage of time asleep by curtailing the amount of time spent sleeping. Allowable time in bed should be initially decreased than the usual time but not less than 5 hours and then increased 15 to 30 minutes every night when the efficiency improves till recommended sleep duration (7 to 9 hours for Insomnia - Definition, Types, Symptoms and Diagnosis adults) is achieved.6

Stimulus control therapy: Stimulus control therapy involves limiting the maladaptive behaviors like eating heavy meals just before bed, late-night use of screens such as mobiles, laptops. Instead promotes the use of bed only for sleeping.2

Relaxation therapy: Regular practice of relaxing breathing exercises, yoga, mindful meditation helps in improving the pattern of sleep and reduce the underlying stress and anxiety. It also helps in improving the attention and efficacy at work.2

Cognitive-behavioral therapy (CBT): Many sleep experts recommend CBT as the first line of non-pharmacological treatment. The main focus of CBT is to find out why someone is having problems with sleep by identifying patterns of thinking and behavior that prevent quality sleep. The treatment approach in CBT includes relaxation therapy, talk therapy, and feedback. These days smartphone-based apps can also be used as a medium for remote therapy session in CBT.9

Pharmacological management:

Medicines or pills are considered useful in patients with chronic insomnia when patients cannot comply with non-pharmacological strategies. Pharmacotherapy can be useful in treating patients but should be used in conjunction with behavioral and cognitive therapies only. Currently available pharmacological treatments include the use of hormonal therapy such as melatonin and over the counter drugs such as antihistamines, sedatives, anti-anxiety, antidepressants, anti-convulsants and anti-hypnotics.6 Insomnia - Definition, Types, Symptoms and Diagnosis

Sleeping medicines can be useful in patients with short periods only in cases of insomnia due to traveling or new time zone or changing work shifts from day to night time. Their use should be limited to less than 4 weeks only. They are always associated with serious side effects, like addiction so the use should be restricted and limited especially in older age groups. Taking prescribed sleeping pills with opioid pain medications can seriously increase the dangers of side effects and should be avoided. It is always advisable to consult your doctor before taking any over the counter drugs for insomnia.9

Complications of insomnia:

Untreated and undiagnosed acute or chronic insomnia can lead to an increased risk of several complications:

Insomnia and cardiovascular disease: chronic insomnia or persistent loss of sleep increases the risk of dysregulation in neurohormonal centers of brain which in turn leads to an increase in inflammatory activity in the body, amplifying the risk of cardiovascular comorbidities such as hypertension, reduced heart rate, and increased risk of infarction.2

Insomnia and diabetes mellitus: inadequate sleep or chronic insomnia is highly associated with an increased risk of type 2 diabetes mellitus (T2DM). It has been estimated that chronic insomnia of <4, 4-8, and >8 years, increases the risk of T2DM by 14%, 38%, and 51% respectively. The reason for this has been associated with the dysregulation of neurohormonal control in the brain with an increase in the blood cortisol levels, impairment in glucose metabolism, and imbalance in hunger-satiety hormones.2

Insomnia and gastric reflux: A bidirectional association has been found between insomnia and Insomnia - Definition, Types, Symptoms and Diagnosis gastric reflux symptoms. Studies have reported increased sleep disturbances, difficulty in initiating, and maintaining sleep in patients with Gastroesophageal Reflux Syndrome (GERD). An increase of 3-fold in the occurrence of GERD has also been reported in patients with insomnia.2  

Insomnia and respiratory system: Chronic insomnia is associated with increased levels of inflammatory mediators in the body which could increase the risk of respiratory problems because of the allergic reactions. Optimal management of chronic insomnia can help in reducing the inflammatory mediators and subsequent airway inflammation.2


Insomnia is a major public health concern affecting the quality of life in about one-third of the population of the United States. Insomnia can present as acute or chronic depending upon the duration and can be considered as a primary health concern or secondary to various comorbidities. Insomnia is associated with impairment of cognitive, physical, and a wide range of daytime functioning domains. Compared to a quality sleeper, people with increased sleep disturbances generally present with a decreased performance at work, increased risk of health problems, loss of concentration, and overall decreased quality of life.


Q1. What is insomnia?

A1. Insomnia is a sleep disorder that refers to any difficulty sleeping, including problems falling asleep, frequent episodes of awakenings in between the sleep, or getting the sleep that is not refreshing. Insomnia - Definition, Types, Symptoms and Diagnosis

Q2. Do women suffer more than men from insomnia?

A2. Yes, it’s true. Women suffer more frequently than men from insomnia. Hormonal changes during premenstrual, menstrual, pregnancy, and menopausal years highly influence the experience of sleep. Women are more likely to develop medical conditions that cause secondary insomnia such as depression, anxiety, other sleep disorders.

Q3. If I don’t have any issues in falling asleep but I wake up in the middle of the night and can’t go back to sleep, is it insomnia?

A3. Insomnia is characterized by several symptoms some patients find it difficult to fall asleep (sleep-onset insomnia), some patients have difficulty in maintaining the continuity of sleep, and some experience waking up too early before the desired time (early morning insomnia).

Q4. What causes insomnia?

A4. Insomnia can be caused by various factors such as improper sleep and lifestyle habits. Other than the environmental and behavioral precipitating and risk factors, it can follow as a symptom of an underlying disorder such as depression, chronic anxiety, hormonal changes, pregnancy, sleep apnea, pain, heart, and lung problems.

Q5. What are the symptoms of insomnia?

A5. Individuals with insomnia are mainly characterized by the following symptoms:

– Non-restorative sleep Insomnia - Definition, Types, Symptoms and Diagnosis

– Fatigue

– Tiredness

– Lack of energy

– Difficulty in concentrating and thinking

– Mood swings

– Irritability

– Impulsiveness and aggression

– More prone to accidents and errors

– Concerns and worries about not getting enough sleep

Q6. For how long does insomnia last?

A6. Insomnia can be short-term, that even for one night called transient insomnia or it could be long-term or chronic insomnia. Some people live with insomnia for years and adapt to it as their normal sleep pattern. Most adults require sleep between 7 to 9 hours per night. Sleeping for less than 3 hours of sleep is abnormal.

Q7. Is it treatable?

A7. Insomnia is very well treatable with just behavioral and environmental modifications. Chronic forms are insomnia can be treated by pharmacological means. Since insomnia is an important sign and secondary symptom of multiple health issues, it is important to diagnose the primary root cause before treating insomnia or secondary sleep disturbances. The main treatments can include prescription sleep aids, sleep hygiene, alternative behavioral, and cognitive therapies. Insomnia - Definition, Types, Symptoms and Diagnosis

Q8. What is secondary insomnia?

A8. It is the form of insomnia that is secondary to other health-related problems such as:

– Depression, anxiety, post-traumatic stress

– Pain

– Heart and lung diseases

– Medications

– Caffeine, tobacco, and alcohol consumption

– Changes in sleep routine or work shift or jet lag

– Poor environmental conditions

Q9. Is insomnia life-threatening?

A9. If insomnia is a secondary symptom to serious health problems such as obstructive or complex sleep apnea then it can be life-threatening. Insomnia itself is treatable with behavioral modifications but in presence of a complex root cause, this could be dangerous.

Q10. What can I do to treat insomnia before seeking medical help? Insomnia - Definition, Types, Symptoms and Diagnosis

A10. Before seeking medical help, an individual should attempt to establish better sleep hygiene as well as modify their behavior and lifestyle habits. Some of the important practices include maintaining a consistent sleep schedule, exercise regularly, avoid caffeine, alcohol, tobacco, and other stimulating agents before bed-time and limiting screen time to at least 30 minutes before going to bed. Other than these, maintaining a comfortable and ambient environment with minimum external distractions helps in improving the overall quality of sleep.


  1. Bragg S, Benich JJ, Christian N, Visserman J, Freedy J. Updates in insomnia diagnosis and treatment. Int J Psychiatry Med. 2019 Sep;54(4-5):275-289. doi: 10.1177/0091217419860716.
  2. Bollu PC, Kaur H. Sleep Medicine: Insomnia and Sleep. Mo Med. 2019;116(1):68-75.
  3. Harvey AG, Tang NK. (Mis)perception of sleep in insomnia: a puzzle and a resolution. Psychol Bull. 2012;138(1):77-101. doi:10.1037/a0025730
  4. Sutton EL. Insomnia. Med Clin North Am. 2014 May;98(3):565-81. doi: 10.1016/j.mcna.2014.01.008.
  5. Kaur H, Spurling BC, Bollu PC. Chronic Insomnia. [Updated 2020 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from:
  6. McCall WV. Diagnosis and management of insomnia in older people. J Am Geriatr Soc. 2005;53(7 Suppl): S272-7. doi: 10.1111/j.1532-5415.2005.53393.x.
  7. Bastien CH, Vallières A, Morin CM. Precipitating factors of insomnia. Behav Sleep Med. 2004;2(1):50-62. doi: 10.1207/s15402010bsm0201_5.
  8. Stepanski EJ, Wyatt JK. Use of sleep hygiene in the treatment of insomnia. Sleep Med Rev. 2003;7(3):215-25. doi: 10.1053/smrv.2001.0246.
  9. Incze M, Redberg RF, Gupta A. I Have Insomnia-What Should I Do? JAMA Intern Med. 2018;178(11):1572. doi:10.1001/jamainternmed.2018.2626.

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