Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
Hypersomnia is a condition that causes prolonged nighttime sleep or persistent episodes of excessive daytime sleepiness.
It must not be confused with symptoms associated with jet lag, acute insomnia, or intense physical exertion leading to fatigue and sleepiness. People with hypersomnia can have sufficient sleep but experience symptoms of hypersomnia or extreme daytime sleepiness.
Types of Hypersomnia
Hypersomnia is divided into two main groups: primary and secondary.
When the condition manifests in a person without any symptoms, other than fatigue or inexplainable lethargy, they have primary hypersomnia.
Secondary hypersomnia occurs when the condition is associated with other medical conditions, like Parkinson’s, sleep apnea, or chronic fatigue syndrome.
Narcolepsy is a different condition that falls under the category of hypersomnolence, and must not be confused with hypersomnia.
The difference between the two conditions is that a hypersomniac can force themselves to stay awake, whereas a narcoleptic type 1 will spontaneously lose voluntary muscle control, known as a “sleep attack” or cataplexy, appearing to be in a state of sleep.
Those with narcolepsy type 1 may also experience hypnogogic hallucinations and sleep paralysis, further differentiating these two conditions.
Studies show that neurotransmitters called hypocretin-1, which promote wakefulness, are deficient in those with narcolepsy type 1, but are within a normal range for hypersomnia patients.[2,3]
Narcolepsy type 2 is characterized by recurrent hypersomnia, but requires a diagnosis. Diagnostic tools, such as polysomnography and multiple sleep latency test, measure the frequency of sleep-onset rapid eye movement occurrences to determine if symptoms are due to narcolepsy type 2.
Kleine-Levin syndrome (KLS) is another disorder that is characterized by recurrent hypersomnia; however, symptoms also include specific cognitive and behavioral issues, including hypersexuality and a disconnection from reality.
Primary hypersomnia occurs when brain functions that control the sleep-wake cycle are disrupted.
Secondary hypersomnia can be a side effect of conditions or diseases that cause fatigue. One such condition is obstructive sleep apnea; a sleep disorder that prevents restorative sleep due to pauses in breathing while sleeping.
Prescribed medications or the use of drugs and alcohol can cause hypersomnia, as well as brain surgeries or injuries, and low thyroid function. These factors may cause an imbalance in normal brain function and lead to hypersomnia.
The most apparent symptom of hypersomnia is chronic and persistent fatigue. A person with hypersomnia may have difficulty waking up from long periods of sleep or may require naps every few hours to function throughout the day. Additional symptoms may include:
- Lack of Energy for Routine Tasks
- A General Decrease in Physical Activity
- Memory Loss
- Weight Loss
If a person suspects that they have hypersomnia, it’s useful to keep a sleep diary for about a month before visiting the doctor. This way the doctor can accurately track sleep patterns, time of sleep, and sleep duration for analysis.
Your Doctor will likely obtain a comprehensive history of your symptoms, including sleep-related habits, your current medications, and drug use. You may be asked to track your sleep using a sleep diary. Additional testing may be needed, such as:
- Sleep Study/Polysomnography to rule out other sleep-related conditions, like sleep apnea, restless legs syndrome, and periodic limb movement disorders
- MSLT: Multiple Sleep Latency Test, which is conducted multiple times during the day to measure how long it takes you to fall asleep to rule out narcolepsy
Treatments for hypersomnia directly depend upon its cause. If it is primary hypersomnia, the doctor may treat it with drugs used for narcolepsy, including amphetamine, methylphenidate, modafinil, and amordafinil. The doctor might also use anti-depressants and supportive therapy to treat hypersomnia, depending on their condition.
If it’s secondary hypersomnia, the doctor will first treat the underlying problem that led to symptoms. Along with it, therapy could be prescribed, like exercise, diet, or lifestyle changes, which could help resolve the hypersomnia.
Be it primary or secondary hypersomnia, diagnosis and therapy play a significant role in correcting hypersomnia. One might be asked to follow a healthy sleep hygiene regimen, which includes:
- A Regimented Sleep and Wake Schedule
- A Cool, Dark Bedroom with Ambient Sound, like a Fan or White Noise Machine or App
- Avoidance of Beverages, like Caffeine and Alcohol
Please note that hypersomnia is usually chronic. It may be treated once and then show up again. In primary hypersomnia, patients might feel relief as long as they willingly stick to their treatment program. People with secondary hypersomnia, who have other conditions, like obstructive sleep apnea or Parkinson’s, may have difficulty establishing a permanent and satisfactory management plan.
- Chen, J. C., Tsai, T. Y., Li, C. Y., & Hwang, J. H. (2015). Obstructive sleep apnea and risk of Parkinson’s disease: a population‐based cohort study. Journal of sleep research, 24(4), 432-437. https://onlinelibrary.wiley.com/doi/full/10.1111/jsr.12289
- Dauvilliers, Y., Baumann, C. R., Carlander, B., Bischof, M., Blatter, T., Lecendreux, M., Maly, F., Besset, A., Touchon, J., Billiard, M., Tafti, M., & Bassetti, C. L. (2003). CSF hypocretin-1 levels in narcolepsy, Kleine-Levin syndrome, and other hypersomnias and neurological conditions. Journal of neurology, neurosurgery, and psychiatry, 74(12), 1667–1673. https://doi.org/10.1136/jnnp.74.12.1667
- Bassetti, C., Gugger, M., Bischof, M., Mathis, J., Sturzenegger, C., Werth, E., Radanov, B., Ripley, B., Nishino, S., & Mignot, E. (2003). The narcoleptic borderland: a multimodal diagnostic approach including cerebrospinal fluid levels of hypocretin-1 (orexin A). Sleep medicine, 4(1), 7–12. https://doi.org/10.1016/s1389-9457(02)00191-0
- Hypersomnia Foundation. (2020, October 19). About Idiopathic Hypersomnia. https://www.hypersomniafoundation.org/ih/
- NINDS. (2019, March 27). Hypersomnia Information Page. https://www.ninds.nih.gov: https://www.ninds.nih.gov/Disorders/All-Disorders/Hypersomnia-Information-Page