Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.

 
 
Similarities and Differences  |  Epidemiology  |  Causes |  Symptoms  |  Risk Factors  |  Diagnosis  |  Treatments

Overview

Hypersomnia and insomnia are two very different sleep disorders. Though disruptions in normal sleep patterns characterize both these conditions, they have different symptoms and manifestations. If not managed properly, both hypersomnia and insomnia can lead to severe consequences. 

It’s important to distinguish between hypersomnia and insomnia to receive appropriate treatment, restore healthy sleep patterns, and avoid complications.

Read on to know the similarities and differences between hypersomnia and insomnia and how to manage these sleep disorders. 

Similarities & Differences

Insomnia’s main symptoms are difficulty falling asleep, remaining asleep, and waking up too early, despite being tired. You may experience poor sleep quality due to physiological or psychological arousal.^[1] You may also have trouble falling back asleep after being awakened.^[2] As a result, you feel unrefreshed and tired during the daytime. 

Insomnia can be classified as primary or secondary. Primary insomnia refers to a difficulty in sleeping that’s unrelated to any medical, environmental, or psychiatric cause, including stress, depression, side effects of medications, or drug abuse.

Secondary insomnia refers to a form of insomnia that’s related to comorbid medical illness, psychological disorder, and other sleep disorders, like sleep apnea or restless leg syndrome.

Hypersomnia refers to a sleep disorder characterized by excessive daytime sleepiness that’s generally unrelated to sleeping well at night.

Hypersomnia can be divided into two categories: idiopathic (primary) and secondary. Idiopathic hypersomnia often develops gradually over the course of weeks and months without a readily discernable cause.

Secondary hypersomnia may occur due to other medical conditions, such as obstructive sleep apnea, Parkinson’s disease, restless legs syndrome, chronic fatigue syndrome, or renal failure.

While idiopathic hypersomnia typically affects adolescents and young adults, insomnia is more common in older adults and women.

Epidemiology

It is estimated that insomnia affects nearly 30 percent of the adult population across the world. Idiopathic hypersomnia is less prevalent compared to insomnia. It is estimated to affect 20 to 50 cases per million population, with no clear gender association.^[3][4][5][6]

Causes

For the most part, hypersomnia and insomnia have different causative factors. The causes of insomnia usually depend on the type of sleeplessness experienced.

Acute (short-term) insomnia can be caused by mental stress, a recent traumatic event, physical pain, or a change in your sleep habits. Chronic (long-term) insomnia lasts for more than three months. 

In some instances, the primary cause of idiopathic hypersomnia can remain unknown; however, some studies suggest that the illness can be precipitated by a viral infection, leading to an autoimmune response.

In 138 patients with hypersomnia, there was a strong prevalence of inflammatory disorders, allergies, and families with inflammatory disorders compared to controls.^[7] 

Another study showed differences in brain volume and cortical thickness and resting functional connectivity.^[8]

Causes of Chronic Insomnia

• Sleep disorders, like obstructive sleep apnea or restless legs syndrome
• Drug and alcohol abuse
• Stimulants, like caffeine or nicotine 
• Comorbid complications from conditions, like diabetes, heart disease, or respiratory disease
• Chronic pain, due to arthritis, back pain, or cancer
• Psychological conditions, such as anxiety or depression

Causes of Idiopathic Hypersomnia

• Viral infection
• Inflammatory disorders, like allergies
• Physiological differences in the brain
• Genetics
• Medications

Causes of Secondary Hypersomnia

• Sleep disorders, like restless legs syndrome and obstructive sleep apnea
• Side effects of medications
• Frequent alcohol and drug use 
• Low thyroid functions due to hypothyroidism
• Atypical depression
  
  

Symptoms 

Commonly shared symptoms of insomnia and hypersomnia:

• Desire to take frequent naps during the day
• Unrefreshing sleep
• Daytime fatigue
• Irritability
• Mood changes
• Increased risk of accidents
• Low energy
• Cognitive deficits causing reduced attention span and memory
• Difficulty in concentrating during the daytime
• Anxiety
• Slow speech and thinking 
• Emotional disturbances 
• Impaired personal, professional, and social life ^[9]

Symptoms of Insomnia

• Waking up too early in the morning
• Difficulty in falling asleep
• Fragmented sleep
• Reduced or increased appetite
• Daytime sleepiness

Symptoms of Hypersomnia

• Excessive daytime sleepiness
• Difficulty in waking even from a long period of sleep
• Sleep drunkenness 
• Sleep Paralysis 
• Hypnagogic Hallucinations 
• Constant tiredness
  
  

Risk Factors 

Insomnia may occur at any age. It is more likely to affect older individuals, and more women than men possibly due to the increased chances of developing hormonal imbalances.

The incidence of idiopathic hypersomnia is not gender-specific; however, it typically occurs in young adults between the ages of 10 and 30.

The common risk factors of insomnia and hypersomnia include:

• Pre-existing emotional disorders, like depression or post-traumatic stress disorder
• Pre-existing sleep disorders, like obstructive sleep apnea
• Pre-existing brain conditions
  
  

Insomnia Diagnosis

Diagnosis of insomnia can be based on a physical examination, symptoms, and test results. 

• The physical examination is aimed at looking for the signs of disorders related to loss of sleep. A blood test may be performed to check for thyroid disorders or other conditions commonly associated with insomnia. 
• You will also be asked to complete a questionnaire to ascertain your sleep-wake pattern and the level of daytime drowsiness. 
• Keeping a sleep diary for a few weeks is also a good way to diagnose insomnia and detect its cause.
• Polysomnogram, a test that involves monitoring your brain activities, eye movements, oxygen levels, heart rate, and breathing functions with the help of a machine, is commonly recommended for the diagnosis of insomnia. ^[10]
• Diagnostic tests for insomnia also include methods to detect obstructive sleep apnea and restless legs syndrome. 
  

Hypersomnia Diagnosis

Hypersomnia is diagnosed based on the review of your symptoms and medical history. A physical examination may be performed to test for alertness. Tests commonly used to diagnose hypersomnia include:

• Sleep Diary: Keeping a record of your sleep times and awake times throughout the night can help the doctor track your sleeping pattern and diagnose hypersomnia.
• Epworth Sleepiness Scale: The severity of hypersomnia can be determined by rating your sleepiness based on the parameters described in this scale.^[11]
• Multiple Sleep Latency Tests: During this test, you take a monitored nap during the daytime. This test measures the type of sleep you experience.
• Polysomnogram: Your doctor may recommend polysomnogram to confirm the diagnosis of hypersomnia. 
  
  

Treatments for Hypersomnia

Medications

Medications that promote alertness may be prescribed to allow patients a chance to cope with their daily lives and to avoid risk factors in the interim.

The use of stimulants to promote activity throughout the day remains an uncertain solution in most cases; however, particularly those where the patient’s hypersomnia is caused by neurological disorders.

Still, these are often applied as a means of both treatment and diagnosis. Physicians can measure reactions to ascertain if the underlying problems are more than sleep deprivation and if a neurological analysis is necessary.

Behavioral Treatments

Physicians may apply behavioral treatments if the cause of hypersomnia is deemed psychosomatic to address mental health disorders, such as clinical depression.

Common sense solutions are applied, such as the prohibition of operating machinery during certain hours to mitigate the associated risks. Doctors may also adjust or prohibit the use of medications and other agents that cause drowsiness.

Treatments for Insomnia

Cognitive Behavioral Therapy (CBT-I)

CBT-I is usually the first-line treatment for patients with chronic insomnia. CBT-I is a treatment that is grounded in the science of behavioral change, psychological theories, and the science of sleep.

Conclusion

It should be noted that both the lack of sleep as well as excessive sleepiness are harmful to your health. Early detection of insomnia and hypersomnia would help you seek appropriate treatment and enable you to restore a healthy sleep pattern.

References:

1. Roth T. (2007). Insomnia: definition, prevalence, etiology, and consequences. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 3(5 Suppl), S7–S10.
2. Levenson, J. C., Kay, D. B., & Buysse, D. J. (2015). The pathophysiology of insomnia. Chest, 147(4), 1179–1192. https://doi.org/10.1378/chest.14-1617
   
3. Anderson, K. N., Pilsworth, S., Sharples, L. D., Smith, I. E., & Shneerson, J. M. (2007). Idiopathic hypersomnia: a study of 77 cases. Sleep, 30(10), 1274–1281. https://doi.org/10.1093/sleep/30.10.1274
4. Bassetti, C., & Aldrich, M. S. (1997). Idiopathic hypersomnia. A series of 42 patients. Brain : a journal of neurology, 120 ( Pt 8), 1423–1435. https://doi.org/10.1093/brain/120.8.1423
5. Coleman, R. M., Roffwarg, H. P., Kennedy, S. J., Guilleminault, C., Cinque, J., Cohn, M. A., Karacan, I., Kupfer, D. J., Lemmi, H., Miles, L. E., Orr, W. C., Phillips, E. R., Roth, T., Sassin, J. F., Schmidt, H. S., Weitzman, E. D., & Dement, W. C. (1982). Sleep-wake disorders based on a polysomnographic diagnosis. A national cooperative study. JAMA, 247(7), 997–1003.
6. Billiard M. (1996). Idiopathic hypersomnia. Neurologic clinics, 14(3), 573–582. https://doi.org/10.1016/s0733-8619(05)70274-7
7. Barateau, L., Lopez, R., Arnulf, I., Lecendreux, M., Franco, P., Drouot, X., Leu-Semenescu, S., Jaussent, I., & Dauvilliers, Y. (2017). Comorbidity between central disorders of hypersomnolence and immune-based disorders. Neurology, 88(1), 93–100. https://doi.org/10.1212/WNL.0000000000003432
8. Pomares, F. B., Boucetta, S., Lachapelle, F., Steffener, J., Montplaisir, J., Cha, J., Kim, H., & Dang-Vu, T. T. (2019). Beyond sleepy: structural and functional changes of the default-mode network in idiopathic hypersomnia. Sleep, 42(11), zsz156. https://doi.org/10.1093/sleep/zsz156
9. Bollu, P. C., Manjamalai, S., Thakkar, M., & Sahota, P. (2018). Hypersomnia. Missouri medicine, 115(1), 85–91. https://pubmed.ncbi.nlm.nih.gov/30228690/
   
10. Practice parameters for the use of polysomnography in the evaluation of insomnia. Standards of Practice Committee of the American Sleep Disorders Association. (1995). Sleep, 18(1), 55–57.
11. Hurlston, A., Foster, S. N., Creamer, J., Brock, M. S., Matsangas, P., Moore, B. A., & Mysliwiec, V. (2019). The Epworth Sleepiness Scale in Service Members with Sleep Disorders. Military medicine, 184(11-12), e701–e707. https://doi.org/10.1093/milmed/usz066