21st Dec 2022
Hypersomnia refers to a condition that involves excessive daytime sleepiness. Hypersomnia might be neurologically-based or caused by medications, drinking too much alcohol, or taking illicit drugs, and usually treated with lifestyle changes or therapy.
Hypersomnia refers to excessive daytime sleepiness. Even after a long night’s rest, a person with hypersomnia might wake up not feeling refreshed. Moreover, patients might be so tired that they fall asleep during the day, even when they’re engaged in an activity like working, eating lunch, or talking with friends or colleagues.
In less severe cases of hypersomnia, patients might sleep throughout the night yet still be so tired that they need to nap several times throughout the day. As a result, people with hypersomnia are often drowsy and feel as though their mind is foggy. Moreover, hypersomnia often causes problems with concentration, memory, and decision-making.
There are two groups of hypersomnia: primary and secondary. While they share some symptoms, these versions of hypersomnia have very different causes.
Primary hypersomnia occurs when there is no known medical cause for the condition. The International Classification of Sleep Disorders (ICSD) Third Edition notes that there are four types of primary hypersomnia:
Narcolepsy is a different disorder that warrants a separate, detailed discussion. For our purposes, we’ll focus on the two other types of primary hypersomnia:
Idiopathic hypersomnia (IH) involves excessive daytime sleepiness, not feeling refreshed from a long night’s sleep or a nap, and difficulty waking up. Furthermore, people with IH often experience mental fogginess, grogginess, and disorientation.
It’s believed that IH is a neurological disorder. Typically, sleep disturbances must occur for three months or more to qualify as IH. It often presents in the teenage years, though in some cases, it appears in childhood or much later in life.
Kleine-Levin Syndrome (KLS) is a very rare type of primary hypersomnia that involves extremely long periods of sleep.
People with KLS sleep for up to 20 hours per day. These sleep episodes occur abruptly, last for several days or weeks, and might not reappear for months. During these episodes, the waking hours might be characterized by abnormal behaviors, like hypersexuality or excessive eating.
KLS mostly occurs in adolescent males and is a chronic condition, though some medications (e.g., stimulants) can help mitigate sleepiness.
Secondary hypersomnia results from other medical conditions, particularly those that disrupt sleep at night. Common medical conditions that cause secondary hypersomnia include:
Furthermore, secondary hypersomnia might occur due to prescription or non-prescription drugs (e.g., opioids, antihistamines, antidepressants) or a psychiatric disorder. For example, people with depression might also have hypersomnia. It isn’t currently understood if hypersomnia causes depression or if depression causes hypersomnia.
Though secondary hypersomnias have similar symptoms (e.g., excessive sleepiness, grogginess, confusion), they vary greatly in their duration. For example, someone with Parkinson’s disease might have chronic hypersomnia. On the other hand, if hypersomnia results from taking medication, the symptoms might stop upon cessation.
Chief among hypersomnia symptoms is excessive daytime sleepiness. As discussed earlier, people with some types of hypersomnia might sleep up to 20 hours per day. This disorder involves symptoms beyond excessive sleepiness, though. For example, additional symptoms might include:
In addition to these generalized hypersomnia symptoms, patients might experience other symptoms related to their specific type of hypersomnia. For example, someone with Kleine-Levin Syndrome might display excessive eating or hypersexuality, as outlined earlier, while someone with idiopathic hypersomnia might not.
The causes of hypersomnia depend on the situation. For example, it’s often much easier to pinpoint a cause of secondary hypersomnia. For example, someone with Parkinson’s disease might have secondary hypersomnia as a result of their medical condition. Likewise, someone that drinks alcohol heavily might be excessively sleepy because of the effects of their alcohol intake.
The cause of primary hypersomnia is more difficult to explain. It might result from a physiological condition, like reduced levels of histamine in the brain. Moreover, low-grade infections or brain damage might also lead to hypersomnia.
Regarding Kleine-Levin Syndrome, one hypothesis is that this type of primary hypersomnia is caused by a malfunction in the brain, specifically in the hypothalamus or thalamus. These areas of the brain control sleep and appetite, which might explain why excessive sleepiness and excessive eating co-occur in KLS.
However, these are simply theories regarding the cause of primary hypersomnia. Since there are no known medical causes for primary hypersomnia, it’s often difficult, if not impossible, to identify why it develops.
In addition to these potential causes, many risk factors make it more likely for hypersomnia to develop. As discussed earlier, alcohol, prescription medications, and non-prescription drugs can all cause hypersomnia. Medical conditions like sleep apnea, restless leg syndrome, and other sleep disorders can also cause excessive daytime sleepiness. Other risk factors include:
A hypersomnia diagnosis requires a physical exam to determine if there are obvious causes (e.g., Parkinson’s or a sleep disorder). Doing so can help medical professionals determine if the condition qualifies as primary or secondary hypersomnia.
Also, medical professionals will ask patients for details about their lifestyles and habits. This line of questioning is needed to determine if environmental factors, medications, or the patient’s emotional state might have something to do with their excessive sleepiness.
Sleep-related tests might be needed to determine if a different condition exists. For example, a doctor might order a sleep study to identify sleep disorders that might cause the patient’s sleepiness. A sleep latency test, which measures how long it takes to fall asleep, might also be necessary.
Lastly, a doctor might order a psychological evaluation to rule out mental health causes for sleepiness, like depression.
According to the DSM-5, primary hypersomnia is part of hypersomnolence disorders. The diagnostic criteria are as follows:
In some cases, secondary hypersomnia might be prevented by changing one’s lifestyle. For example, if a prescription medication is the cause of excessive sleepiness, an adjustment in dosage or changing to a different medication might bring about improved results.
However, most cases of hypersomnia, particularly primary hypersomnias, cannot be prevented. But, with appropriate treatments (discussed below), many patients can effectively manage their symptoms.
The most common type of hypersomnia treatment is medication, including those commonly used to treat narcolepsy. There are three main types of FDA-approved pharmacologic treatments for this disorder:
Other hypersomnia treatment options aren’t FDA-approved. For example, Wellbutrin, an antidepressant, helps promote wakefulness by preventing dopamine and norepinephrine from being absorbed in the brain.
Another option is selegiline (e.g., Eldepryl, Emsam). This monoamine oxidase type B inhibitor slows the breakdown of dopamine, norepinephrine, and serotonin in the brain. As a result, these neurotransmitters become more active, which might help improve wakefulness.
In some cases, melatonin might enhance sleep and caffeine to promote wakefulness in people with hypersomnia. People with Kleine-Levin Syndrome benefit from carbamazepine or lithium - drugs typically prescribed for mood disorders - which might help reduce the frequency of hypersomnia episodes.
Aside from medications, physicians often outline lifestyle changes that can help manage hypersomnia symptoms. For example, patients might be asked to maintain a strict schedule of activity and rest that includes a proper diet, meditation or mindfulness training, and planned naps. Furthermore, psychotherapy, group therapy, and support groups for people with sleep disorders can be beneficial for diminishing anxiety and stress.
It’s also worth discussing hypersomnia with loved ones. The more they understand what’s going on, the more capable they will be of offering assistance.
Hypersomnia can significantly impact a person’s ability to function, including in social and occupational realms, because of their level of sleepiness. Likewise, people with hypersomnia might not be able to drive because of the likelihood of falling asleep behind the wheel.
It’s estimated that hypersomnia affects four to six percent of the general population. Men are more likely than women to have this disorder.
Hypersomnia and narcolepsy are closely related. However, a primary difference between the two is that narcolepsy involves the sudden onset of deep sleep, while hypersomnia is characterized by excessive daytime sleepiness.