Just about everyone has days when they can’t keep their eyes open, and they just feel drained of energy. However, for some people, excessive daytime sleepiness (EDS) isn’t just the consequence of a poor night’s sleep, a bout of stress, or the side effects of a new medication. For those individuals, EDS, also known as hypersomnia, is a symptom of a potentially serious, chronic medical condition.
Hypersomnia is usually categorized as primary or secondary. Secondary hypersomnia occurs when a health condition, medications, or certain behaviors cause you to feel extreme sleepiness. Those conditions can include alcohol or drug use, depression, head injury, or problems getting enough high-quality sleep or sleeping each night enough.
Primary hypersomnia, however, usually falls into one of three categories, explains John Winkelman, MD, PhD, a Massachusetts General Hospital sleep specialist. These categories are considered central nervous system (CNS) hypersomnias because they are neurological sleep disorders in which the brain can’t properly regulate the sleep-wake cycle. CNS hypersomnias include narcolepsy type 1, narcolepsy type 2, and idiopathic hypersomnia.
What Is Hypersomnia?
Hypersomnia means you feel extreme sleepiness during the day, even though you may have had plenty of sleep the night before. You also may experience other symptoms, such as anxiety or irritability, low energy, confusion, and difficulty becoming fully awake and attentive in the morning or after a daytime nap. Hypersomnia is sometimes accompanied by headaches, appetite changes, and memory problems. People with narcolepsy often fall asleep suddenly and may experience hallucinations or sleep paralysis (a temporary inability to move or speak), both of which occur while falling asleep or waking up. Another symptom, called cataplexy, is one of the main features distinguishing narcolepsy type 1 from type 2. Cataplexy is a sudden, brief loss of muscle tone that usually coincides with strong emotions, such as laughter, surprise or anger.
Cataplexy, sleep onset and offset hallucinations, and sleep paralysis may all be manifestations of aspects of REM sleep (paralysis, dreams) breaking through into wakefulness. Cataplexy, a feature of narcolepsy type 1, but not type 2, is related to low levels of the brain hormone orexin (also known as hypocretin). People with narcolepsy type 2 have normal levels of orexin. The same is true for people with idiopathic hypersomnia. Orexin levels are checked by measuring the hormone’s concentration in cerebrospinal fluid, which is obtained with a lumbar puncture (spinal tap).
Dr. Winkelman says the differences between narcolepsy type 2 and idiopathic hypersomnia represent “a gray area,” as some symptoms are similar. However, people with idiopathic hypersomnia tend to sleep longer at night (often more than 11 hours), have difficulty awakening from sleep (“sleep inertia”) and take longer, though unrefreshing, naps. Individuals with narcolepsy type 2 usually sleep normal amounts at night and can take shorter, but temporarily more refreshing, naps compared with people who have idiopathic hypersomnia. Both conditions lead to EDS without cataplexy.
Dr. Winkelman notes that having idiopathic hypersomnia—the causes of which remain unknown—can be particularly stressful. “It’s hard to live a normal life and get 11 hours of sleep at night,” he says.
Why Do I Sleep So Much?
If you suspect you might have some form of hypersomnia, Dr. Winkelman recommends seeing your primary care physician first and explaining your symptoms and concerns. You may be advised to see a sleep specialist and undergo an overnight sleep test, to assess for other sleep disorders (such as obstructive sleep apnea) in which potential disruptions to sleep quality will be assessed.
To check for hypersomnia, your doctor may suggest you continue the medical evaluation the next day with a multiple sleep latency test (MSLT). The goals of an MSLT are to see how fast you fall asleep and how quickly you reach REM sleep—the dream stage and a crucial phase for memory consolidation and mood regulation, among other functions.
For an MSLT, you are given five opportunities to nap during the day. You have 20 minutes to fall asleep each time and are allowed to sleep no longer than 15 minutes. And you can’t sleep between the nap tests. Dr. Winkelman explains that people who have EDS usually fall asleep in less than eight minutes. He also notes that if you go into REM sleep during at least two of the naps, you may be diagnosed with narcolepsy.
Getting an official diagnosis helps people make sense of their symptoms, so it’s important not to ignore ongoing symptoms. The right diagnosis also allows you and your health-care provider to map out a treatment plan.
Hypersomnia Treatment
The main treatment options for both types of narcolepsy are stimulants such as amphetamines (e.g. Adderall, Vyvanse) or methylphenidate (e.g. Ritalin); wake-promoting agents, such as solriamfetol (Sunosi) and modafinil (e.g. Provigil), both taken during the day; or sodium oxybate (e.g. Xyrem, Lumryz), a general anesthetic, which is taken at night. Several drugs used to treat hypersomnia are prescribed off-label, meaning they are not officially FDA-approved for that condition, though they have been shown to be effective for many people.
In addition, avoidance of sleep deprivation and using daytime naps to improve daytime wakefulness, are important.
Some potential new hypersomnia treatments on the horizon could make a big difference for people with narcolepsy type 1, Dr. Winkelman says. Drugs called orexin agonists are in development, and early research suggests they may help dramatically improve daytime sleepiness and cataplexy. “They’re very far along in development,” he adds. “The benefits could be enormous.” Orexin agonists mimic the action of natural orexin, stimulating the neurons that promote wakefulness, inhibit cataplexy, and stabilize sleep-wake cycles.
Dr. Winkelman suggests that orexin agonists could potentially help some people with narcolepsy type 2, even though those individuals have normal levels of orexin. “The idea is that you might give them doses higher than those for narcolepsy type 1,” he says. “It’s not about addressing the absence of orexin, though. You’re just sort of boosting the system to help them stay awake.”
Managing idiopathic hypersomnia usually involves stimulants and wake-promoting agents, as well as lifestyle adjustments designed to promote a healthy sleep-wake schedule. These behaviors include steps such as going to bed and getting up at the same times every day, avoiding or limiting alcohol and caffeine, and creating a sleeping environment that is as conducive to healthy sleep as possible. That means maintaining a cool, dark bedroom and investing in a mattress and pillows that are comfortable for you.
Whether you have narcolepsy or idiopathic hypersomnia, you may want to work with a therapist familiar with cognitive behavioral therapy for hypersomnia (CBT-H). While CBT-H includes strategies to help with your sleep-wake scheduling, it also focuses on goals such as managing your energy levels during the day, restructuring your thoughts and feelings related to your sleep disorder, and coping with the social and occupational challenges related to chronic sleepiness.
Overcome Hypersomnia
Daytime sleepiness can have many causes, including sleep deprivation, sleep apnea, neurological conditions (Parkinson’s disease, multiple sclerosis, etc.), chronic illnesses (heart failure, thyroid disease, etc.), sedating medications, and others. If you’re having trouble staying awake during the day, don’t assume it’s old age and resign yourself to living this way.
If you have a known condition that contributes to daytime sleepiness, work with your health-care team on strategies to ease your symptoms or better manage your energy levels during the day. If you don’t know why you are so sleepy during the day, see your doctor soon and explain your symptoms. You may be asked several questions about the nature of your daytime tiredness—there’s a difference between being sleepy and fatigued, for example—but that conversation could be the first step toward improving your sleep, wakefulness, and quality of life.
