Hypersomnia refers to either excessive sleepiness during the day or extended, overly long periods of nighttime sleep. Other words that are synonymous with hypersomnia are excessive daytime sleepiness (EDS), excessive sleepiness, or somnolence.
Hypersomnia is fairly common, with nearly 5% of the population affected. The age groups most affected by hypersomnia are teenagers and young adults. As with most sleep disorders, hypersomnia is underreported because many people inaccurately believe that always feeling sleepy and taking naps are normal behavior.
A distinction should be made between simple tiredness, fatigue, or depression, and hypersomnia. Sleep deprivation is a common state for most of the population – many people are tired or sluggish at certain periods during the day. The depressed person either will not want to get out of bed or will suffer from insomnia, even though he or she feels a nap will improve the depression. On the contrary, hypersomniacs are so sleepy during the day that they are compelled to sleep or “take a nap.” These individuals fall asleep during movies, dinner, or even in the conversation. Similarly, they may sleep ten hours or longer during one sleep cycle, rather than the average eight.
There are various types of hypersomnia:
Post-traumatic hypersomnia – This type of hypersomnia may arise from a head injury or a traumatic incident involving the central nervous system. It is usually associated with related symptoms such as headaches, fatigue, memory impairment, as well as difficulty concentrating. Hypersomnia is more commonly seen immediately after the accident, however, in some cases, symptoms are delayed more than a year. Duration of symptoms may last only a short time, can continue for months or years, or can remain indefinitely.
Recurrent hypersomnia – This disorder is characterized by recurring episodes of hypersomnia. Kleine-Levin Syndrome, a disorder that causes individuals to sleep for extended periods of time followed by a normal period of alertness, is a type of recurrent hypersomnia. The length of the episode or the time period between episodes is indeterminate. It may or may not be accompanied by other symptoms such as overeating (also called gluttony or clinically, compulsive hyperphagia) and hypersexuality.
Idiopathic hypersomnia – The term “idiopathic” means without a known cause. This type of hypersomnia is similar to narcolepsy in that the individual is excessively sleepy, falls asleep at inappropriate times, frequently takes naps, and sleeps at night for greater than 10 hours. In some cases of idiopathic hypersomnia, cataplexy and hypnagogic hallucinations may be present and resemble the symptoms of narcolepsy. However, in idiopathic hypersomnia, there is insufficient sleep onset REM periods to justify the diagnosis of narcolepsy. Normal hypersomnia, often a genetic predisposition, a “normal” hypersomniac is one who simply requires more sleep, i.e. more than 10 hours of sleep per day. The problem that results is when sleep patterns and requirements interfere with a daily schedule. These individuals are typically called “long sleepers.”
What Causes Hypersomnia?
There are many potential causes of hypersomnia. The simplest reason for excessive sleepiness during the day or night is a need. If an individual has repeatedly lacked a good night’s sleep, he or she will inevitably compensate for the loss by taking a nap or sleeping longer at night. Most individuals will not allow this trend to continue for an extended period of time and these persons are not diagnosed with clinical hypersomnia.
Causes of Clinical Hypersomnia
- Sleep Deprivation in a naturally long sleeper
- Another sleep disorder or illness
- Central nervous system disorder, damage or dysfunction
- Medical withdrawal
- Certain Medications
- Head injury or trauma
- Genetic predisposition
Hypersomnia may be a symptom of a primary sleep disorder such as Periodic Limb Movement Disorder or narcolepsy. This also applies to certain medical, psychiatric or neurological illnesses.
Hypersomnia can be the result of a central nervous system disorder, tumor, brain damage, or dysfunction. Recurrent hypersomnia is thought to be caused by a hypothalamic dysfunction (located in the hypothalamus). Similarly, post-traumatic hypersomnia is more likely to occur in individuals whose injury involved certain parts of the central nervous system, specifically the hypothalamic or brain stem region, although the specific region is unknown. In the case of the “normal” hypersomniac in which the person requires at least 10 hours of sleep a day, his or her schedule may not accommodate that need, resulting in perpetual sleepiness.
The use or withdrawal of certain medications may also cause hypersomnia. Tranquilizers and sleeping pills, known for their sedative effect, can promote sleepiness during the day. Hypersomnia is often experienced in people attempting to withdraw from caffeine, alcohol, or stimulants.
What Are The Consequences of Hypersomnia?
Excessive sleepiness, napping, and long nighttime sleeping can all interfere with a normal schedule and work routine. Related symptoms of hypersomnia, including irritability, mild depression, memory loss, and lack of concentration, impair performance. For this reason, persons suffering from hypersomnia should be careful when operating machinery, especially driving a motorized vehicle, as accidents are likely to happen.
When Should I See a Doctor?
Hypersomnia may be referred to as excessive sleepiness during the day, the time when many people are awake. Excessive sleepiness is a major complaint of shift workers or individuals who suffer from another sleep disorder. The key to identifying when it is necessary to see a professional is the point at which one’s life or mental good being is disturbed.
How to diagnose from Hypersomnia?
As mentioned above, there are many causes of hypersomnia. It is important for a healthcare provider to analyze and identify the underlying cause. Consultation with a sleep specialist may be necessary. In some cases, a primary care physician will be able to refer patients to a reputable, licensed sleep specialist in the area. Because it is common for people who are suffering from another sleep disorder or medical condition to present with a complaint of excessive sleepiness, a sleep specialist will want to investigate and analyze most patients with an overnight polysomnogram.
One night spent in the sleep clinic may require more testing. To that end, a Multiple Sleep Latency Test (MLST) is a good indicator of excessive sleepiness. It is a test that reveals how quickly a patient falls asleep and whether he/she progresses to REM sleep. For the MSLT, the patient is asked to spend a night in the sleep laboratory to make sure he or she receives adequate sleep and that no other sleep disorders are present. The next day, the MSLT is performed. Electrodes are attached to various areas of the body. The patient is asked to take four or five 20-minute naps every two hours. A diagnosis of excessive sleep is made if the patient falls asleep within 5 minutes of each nap.
Other quantification tests used by sleep specialists for determining excessive sleepiness are the Maintenance of Wakefulness Test (MWT) and vigilance testing. The MWT is similar to an MSLT except that it encourages the patient to remain awake during the designated naptime. This test is useful for establishing the efficacy of certain medications or the ability to operate heavy equipment. Vigilance testing refers to various tests that measure alertness. These can be subjective by self-rating scales, or physiological by pupillometry, MLST, or MWT. Vigilance testing can also include asking the patient to perform tasks that reveal concentration levels.
Subjective tests of sleepiness can be found here on our website. You may assess your sleepiness by using our Sleep Diary (Link to the Sleep Diary page) or the Epworth Sleepiness Scale. The Sleep Diary (Link to the Sleep Diary page) asks you to select the statements that describe your daily (and nightly) behavior. The results of the test may help you ascertain symptoms of a sleep disorder. The Epworth Sleepiness Scale is a short and standard assessment test that estimates, on a scale from 0 – 24, whether you are experiencing excessive sleepiness possibly requiring medical attention.
Please keep in mind that both tests are intended as a general source of information only. A specific diagnosis should not be assumed, as only a trained professional can accurately diagnose and treat medical conditions. Scores from either test neither confirm nor eliminate the possibility that you have a sleep disorder.
How to treat Hypersomnia?
Depending on the cause of the hypersomnia, treatments for various symptoms are available. If the hypersomnia is caused by sleep deprivation, the treatment can be as simple as making more time in one’s schedule to get enough sleep. If it is caused by certain medications, an adjustment to the dosage or time of day, or even a switch to a different drug, may be the solution.
Hypersomnia is the major complaint of patients suffering from other medical conditions or disorders, including other primary sleep disorders. If an underlying medical condition is the cause of the hypersomnia, the principal disorder will need to be treated directly. Treatment of post-traumatic hypersomnia is usually confined to controlling the symptoms of excessive daytime sleepiness. Stimulant medications used to improve mental activity, such as methylphenidate (Ritalin), modafinil (Provigil), Ambien (Zolpidem) or pemoline (Cylert), may be prescribed.
Because recurrent hypersomnia occurs for relatively short, temporary periods of time and on average, twice per year, treatment is largely support-oriented. Informing family, friends, co-workers, and employers of the disorder are the best means of establishing support and understanding. Pharmacologic treatment of recurrent hypersomnia is limited to an “as needed” basis.
Treatment of idiopathic hypersomnia is similar to that of narcolepsy patients. The remaining alert is the goal of treatment for excessive sleepiness. A stimulant medication such as modafinil (Provigil) may be initially prescribed and monitored for an adequate response. Other drugs may be added or considered if initial attempts at treatment are not satisfactory. Lifelong treatment is usually required.