Hypersomnia and narcolepsy are related but separate medical terms. Narcolepsy is a specific neurological disorder that causes sudden attacks of deep sleep, while hypersomnia is a symptom and more generally refers to excessive daytime sleepiness.
Hypersomnia, or hypersomnolence, is a symptom of narcolepsy. It is therefore not possible to compare and contrast hypersomnia and narcolepsy, as they are not separate medical conditions.
But there are other causes of hypersomnia besides narcolepsy, and these conditions have distinct and distinct characteristics.
In this article, we’ll take a more in-depth look at hypersomnia and narcolepsy, including what the terms mean and how they relate. We will also look at narcolepsy in comparison with other causes of severe drowsiness.
Hypersomnia, or hypersomnolence, is a medical term that describes excessive daytime sleepiness. It is a symptom rather than a medical condition.
A person with hypersomnia may need to sleep during the day or sleep longer than average at night. People with this symptom may experience:
- drowsiness or disorientation after waking up
- the need to take frequent naps
- difficulty concentrating
- difficulty remembering
- slow speech
There are two categories of hypersomnia: primary and secondary. Primary hypersomnia is caused by an underlying condition that directly affects the sleep-wake cycle, such as narcolepsy.
Secondary hypersomnia occurs when another thing causes excessive fatigue, such as a medication, head trauma, or a health problem that disrupts sleep in some other way. For example, sleep apnea causes a person to temporarily stop breathing while sleeping, which reduces the quality of sleep and can cause daytime sleepiness.
Narcolepsy is a specific neurological disorder that causes sudden attacks of overwhelming drowsiness that can occur at any time. They can occur when someone is talking, eating, or driving. These attacks last from a few seconds to a few minutes.
One of the causes of primary hypersomnia is narcolepsy. But between attacks, people can have typical energy levels. People with narcolepsy also often experience:
- sleep paralysis, which causes a temporary inability to move or speak when a person falls asleep or wakes up
- hallucinations, which can accompany sleep paralysis and can be frightening
- difficulty staying asleep at night, which can cause frequent awakenings or insomnia
People with type 1 narcolepsy also suffer from cataplexy, which is similar to fainting. Cataplexy causes a sudden loss of muscle tone and control when a person experiences strong emotions. This can lead to a total body collapse or milder symptoms, such as sudden weakness or cataplexy in just one part of the body.
People with type 2 narcolepsy do not have cataplexy.
What causes narcolepsy?
Scientists don’t fully understand what causes narcolepsy. There can be different causes for types 1 and 2.
Almost all people with type 1 narcolepsy have very low levels of hypocretin, a chemical that keeps the body awake and regulates the rapid eye movement (REM) phase of sleep. This may explain why people with narcolepsy enter REM sleep much faster than most people, and why they can have vivid dreams and sleep paralysis.
Researchers believe people can develop type 1 narcolepsy if the cells that produce hypocretin die. This can be due to an autoimmune disease, genetics, or environmental factors.
But those who suffer from narcolepsy without cataplexy tend to have usual levels of hypocretin. The cause of type 2 is currently unknown.
One of the potential causes of primary hypersomnia is narcolepsy, but there are others.
Despite its name, idiopathic hypersomnia (HI) is a separate medical condition named after its most prominent symptom. It is a disorder of the nervous system. Scientists don’t understand what causes it, but the excessive fatigue and unhealthy sleep it causes can be debilitating.
- sleep more than 10 to 11 hours a day
- sleep that does not reduce fatigue
- difficulty waking up, which can lead to disorientation
- mental fog and difficulty concentrating
Another cause of primary hypersomnia is Kleine-Levin syndrome, a rare condition that causes episodes of excessive sleep that occur in cycles. Symptoms include:
- sleep up to 20 hours a day
- behavior changes, such as an unusually high sex drive or lack of emotion
- feeling confused, disoriented, or lethargic when awake
Between episodes, people can go weeks or months without any symptoms. The condition often improves with age, but sometimes returns as a person gets older. The cause of Kleine-Levin syndrome is unknown.
The following table compares narcolepsy with HI and Kleine-Levin syndrome:
Conditions that cause primary hypersomnia, including narcolepsy, are quite rare. In many cases, excessive daytime sleepiness is the result of something else.
Some other causes of severe drowsiness include:
- conditions that disrupt or decrease the quality of sleep, such as sleep apnea
- conditions that affect the brain or nervous system, such as Parkinson’s disease or brain damage
- conditions that impact mental health, such as depression
- drugs that cause drowsiness, such as antihistamines, opiates, and benzodiazepines
Learn more about the potential causes of excessive sleepiness.
Doctors can begin to diagnose the cause of excessive sleepiness by taking a medical history and asking questions about a person’s symptoms. They can also have someone keep a sleep diary for several days, to get a better idea of how much a person sleeps, whether it’s refreshing or not, and what impact it has. has on his life.
Doctors should also rule out other potential causes of fatigue. They can review any prescription or recreational drug a person takes and order medical tests. If there is no clear cause, they can refer someone to a sleep lab.
There are two key tests that a sleep lab can perform:
A polysomnogram (PSG) records muscle and brain activity, eye movements, and breathing during sleep. This allows doctors to determine if REM sleep is occurring earlier in a person’s sleep cycle than it should. It can also detect other causes of daytime sleepiness, such as sleep apnea.
Multiple sleep latency test
A multiple sleep onset latency test examines daytime sleepiness. The day after a PSG, a person must take five short naps, each separated by 2 hours. On average, falling asleep in 8 minutes or less is an indication of excessive daytime sleepiness.
For narcolepsy testing, in some cases, a doctor may also measure the level of hypocretin in the fluid surrounding the brain and spinal cord. But because low levels of hypocretin aren’t characteristic of type 2 narcolepsy, it’s not always helpful.
Treatment for hypersomnia depends on the cause. For hypersomnia caused by narcolepsy, doctors may prescribe medications to help prevent sleep attacks during the day. This may include:
- Drugs promoting arousal: Modafinil (Provigil) is the first-line treatment for narcolepsy. It is a non-stimulating drug promoting arousal. This class of drugs is derived from amphetamines, but causes fewer side effects and is less likely to be addictive.
- Stimulants: Sometimes doctors can prescribe stimulants. But these amphetamine-type drugs can cause a number of side effects and are addictive. Examples include dextroamphetamine (Dexedrine) and methylphenidate (Ritalin).
- Antidepressants: Several types of antidepressants are effective in controlling cataplexy. These include tricyclic antidepressants, selective serotonin reuptake inhibitors, and serotonin and norepinephrine reuptake inhibitors.
- Sodium oxybate: This medicine can also treat cataplexy and hypersomnia in people with narcolepsy. Sodium oxybate is a highly controlled substance due to its potency.
In 2021, the Food and Drug Administration (FDA) approved sodium oxybate for use in people with HI. Currently, it is the only officially approved drug for the disease. But because treatments for narcolepsy can also help with HI, many doctors prescribe them for off-label use.
Managing hypersomnia often involves lifestyle changes. These may include:
- maintain a consistent schedule for activity, rest, and sleep
- exercise daily for at least 20 minutes and at least 4 to 5 hours before sleeping
- avoiding heavy meals before sleeping
- practice relaxation before bedtime
- quit smoking, especially at night
- avoiding caffeine and alcohol
People with primary hypersomnia may also seek additional support in the workplace, at home, and for their mental health. This may include:
- workplace adjustments to allow naps and flexible hours, to which people with narcolepsy are entitled under the Americans with Disabilities Act
- treatment with a therapist to help lessen the impact of hypersomnia on a person’s mood
- support groups for others experiencing the same symptoms or conditions
- a service animal that can wake someone up in an emergency or help with tasks
It is also important that people with hypersomnia take safety precautions. This may mean avoiding certain activities when you feel drowsy, such as driving, going up or down stairs, or using machines.
Hypersomnia refers to excessive daytime sleepiness. In people with narcolepsy, this manifests as brief, sudden sleep attacks, which cause an overwhelming urge to sleep during daily activities. People with narcolepsy can also experience cataplexy, sleep paralysis, vivid dreams, and hallucinations.
Other causes of hypersomnia include HI, Kleine-Levin syndrome, certain medications, and other medical conditions that indirectly affect sleep. Only a doctor or sleep specialist can diagnose the cause.
Excessive sleepiness has a significant impact on quality of life, but treatments and strategies can help minimize symptoms. If someone experiences persistent drowsiness during the day and getting enough sleep doesn’t help, they should talk to a healthcare professional.