Internet Explorer is no longer supported on our website. We recommend using Google Chrome, Mozilla Firefox, Apple Safari, or Microsoft Edge
Learn about compatible browsersNarcolepsy and Other Hypersomnia Disorders
Overview
When you don’t get enough sleep at night, it’s common to feel sleepy during the daytime. This happens to everyone from time to time. However, when daytime tiredness becomes frequent and overwhelming, it’s called hypersomnia. This condition can be hazardous and lead to accidents, injuries, and the inability to complete regular family and work activities.
Primary hypersomnia is a discrete condition and includes narcolepsy and Kleine-Levin syndrome. Secondary hypersomnias have an underlying cause, such as sleep disorders, psychiatric disorders, medication use, and substance abuse.
Causes and Symptoms of Primary Hypersomnia
Narcolepsy
Narcolepsy prevents patients from controlling their normal sleep-wake cycles. This can cause hypersomnia.
Each type has different symptoms.
- Type 1 causes excessive daytime sleepiness and cataplexy, which consists of episodes of muscle weakness. Symptoms include knees that give way or slurred speech. Some people experience paralysis-like symptoms. These events are usually triggered by strong emotions such as surprise, laughing at something, or anger.
- Type 2 narcolepsy consists of being severely tired during the day, often falling asleep during activities. However, the muscles are not affected.
Causes
Narcolepsy is caused by a lack of CSF hypocretin-1. Hypocretin is a brain messenger that regulates wakefulness and appetite. Some people with narcolepsy have low levels of hypocretin, others have none.
Idiopathic hypersomnia (IH)
This is a rare sleep disorder that causes daytime sleepiness and sleeping. Patients can fall asleep during the day even though they slept well the night before. Other symptoms include:
- An inability to function at work or school. This may lead to job loss or dropping out of college.
- Memory problems. Someone with IH may forget how to do routine tasks, be forgetful, and feel like they have brain fog.
- Headaches.
- Dizziness.
- Cold hands and feet.
We don’t know what causes IH. However, several factors may increase the risk of developing the condition. These include:
- Infections. It’s possible that IH may be triggered by a viral or bacterial infection.
- Brain abnormality. Researchers don’t yet know if this could be a cause. However, there may be connections between the level of certain brain chemicals, such as histamine, and the development of IH.
Kleine-Levin syndrome (KLS)
KLS causes episodes of extreme daytime sleepiness and hypersomnia alternating with normal sleep/wake cycles. Because patients with KLS can sleep for many hours, it’s also known as "sleeping beauty syndrome." Other names include recurrent hypersomnia or periodic hypersomnolence. Extensive sleep can impact a patient’s ability to continue their regular activities.
Symptoms include:
- Sleeping for long periods, often up to 18 hours. This may continue for a few days but sometimes a few weeks. These episodes of extended sleep may repeat weeks or months later. They can occur once or twice a year or up to 10 times a year.
- Overeating.
- Aggressive behavior.
- Other psychiatric symptoms.
Causes and Symptoms of Secondary Hypersomnia
Secondary hypersomnias are caused by an underlying primary medical condition.
Insufficient sleep syndrome
Insufficient sleep syndrome is caused by not getting enough sleep. People with insufficient sleep syndrome:
- Don’t prioritize sleep. They get less than 7 to 8 hours a night.
- Know they should get more sleep but stay up late to read a book, get work done, or use the phone in bed.
- Experience brain fog, irritability and fatigue during the day.
- May have a partner or family member who needs less sleep than they do.
- Notice that daytime sleepiness improves when they get at least 8 hours of sleep.
- Typically don’t have any medical conditions or sleep disorders that might cause daytime sleepiness.
Sleep disorders
Some sleep disorders can cause hypersomnia. They include:
- Sleep-related breathing disorders such as sleep apnea.
- Circadian rhythm sleep-wake disorders. These can include delayed sleep-wake phase disorder, where the body naturally doesn’t feel sleepy until the early hours of the morning and then can’t wake until late morning.
- Sleep-related movement disorders. These can include restless legs syndrome and periodic limb movement disorder. These conditions disrupt sleep and then cause hypersomnia symptoms during the day.
Medical disorders
Medical disorders that can cause hypersomnia include:
- Neurologic disorders. People with Parkinson’s disease or multiple sclerosis are at increased risk of developing hypersomnia.
- Genetic disorders. Some rare genetic disorders (such as Prader-Willi syndrome and Niemann-Pick type C) are associated with hypersomnia and other sleep disorders.
- Metabolic conditions such as hypothyroidism and hepatic encephalopathy can cause hypersomnia. Hepatic encepatholopathy is a brain condition that occurs when the liver doesn’t filter toxins from the blood correctly.
Psychiatric disorders
When hypersomnia is caused by a psychiatric disorder it may cause sleeping for long periods of time at night, sometimes 20 hours. Other symptoms include daytime sleepiness and long naps. Examples of psychiatric conditions that can cause hypersomnia include:
- Anxiety.
- Somatic symptom disorder. This is associated with hyperfocus on physical symptoms, such as pain, breathing, or weakness.
- Depression. This includes bipolar depression.
Medication and substance abuse
Many medications, when taken too frequently or without medical advice, can cause excessive sleeping and sleepiness during the day. They include:
- Benzodiazepines
- Nonbenzodiazepine sedatives
- Antihistamines
- Anticonvulsants
- Opioid analgesics
- Sedating antidepressants
- Antipsychotics
- Alcohol
- Narcotics
Diagnosis
Talk to your doctor if you’re overtired during the day and frequently feel the need to sleep or fall asleep at work or school. They may refer you to a sleep specialist for a complete evaluation and diagnosis.
Tests may include:
- Home sleep apnea testing. Learn more about sleep studies here.
- Polysomnogram (PSO). This is a type of sleep study that records brain waves, eye movements, and breathing during sleep. This is typically done in the medical offices but can be done during the day or at night. This test is usually combined with a multiple sleep latency test.
- Multiple sleep latency test (MSLT). This is a nap test typically taken the day after the PSO test is done. It measures how quickly a person falls asleep and enters REM sleep. Some people take multiple naps during this test. It can help diagnose narcolepsy and idiopathic hypersomnia.
- Actigraphy. You’ll wear a wristwatch-like device called an actigraph as you go about your daily activities. It's usually worn for several days and nights and records when and how often you sleep.
Lifestyle Recommendations
There are many things you can do to improve the quality of sleep at night that may help reduce your symptoms. Sleep hygiene is a set of habits and routines that ensure you get enough sleep. These routines are particularly helpful for people with insufficient sleep syndrome.
The main steps include:
- Getting regular daily exercise. For example, walk for 30 minutes every day.
- Getting 7 to 8 hours of sleep each night.
- Practicing relaxation, like deep breathing, yoga, or playing with a pet.
- Eating breakfast and regular, healthy meals.
- Limiting caffeine to the hours before noon.
- Going to bed at the same time every night and waking at the same time each morning.
Learn about sleep hygiene here.
Treatment
Your doctor will talk to you about treatment options. This may include medications, particularly if your hypersomnia is caused by narcolepsy. Your sleep doctor may prescribe a stimulant or a wake-promoting medication such as modafinil to help you stay awake during the day. Some of these medications can have significant side effects so your doctor will schedule regular appointments to monitor your health.
Hypersomnia treatment programs may also include:
- Encouraging you to sleep at the same time each night and wake up at the same time each day.
- Taking prescribed medications so you can function at work or school.
- Avoiding driving if you feel sleepy.
- Avoiding certain medications that may affect sleep and sleepiness.
- Avoiding alcohol.
- Treating any other sleep disorders, such as narcolepsy or circadian rhythm sleep-wake disorder.
- Treating any underlying medical or psychiatric conditions.