Hypersomnia is a disorder characterized by excessive amounts of sleepiness. There are two main categories of hypersomnia: primary hypersomnia (also called idiopathic hypersomnia) and recurrent hypersomnia (also called primary recurrent hypersomnia). Both have the same symptoms but differ in how often they occur.
Those who suffer from hypersomnia have recurring episodes of excessive daytime sleepiness (EDS) which is different from feeling tired due to lack of or interrupted sleep at night. They are compelled to nap repeatedly during the day, often at inappropriate times such as at work, during a meal, or in conversation. These daytime naps usually provide no relief from symptoms.
Patients with hypersomnia often experience prolonged night sleep and have difficulty waking from long sleep, feeling disoriented upon doing so. Other symptoms may include anxiety, increased irritation, decreased energy, restlessness, slow thinking, slow speech, loss of appetite, hallucinations, and memory difficulty. Some patients lose the ability to function in family, social, occupational or other settings. Typically, hypersomnia is first recognized in adolescence or young adulthood. These symptoms are present in both types of hypersomnia. A sufferer from primary hypersomnia displays these symptoms continually for months or even years. Recurrent hypersomnia is characterized by recurring periods of symptoms many times throughout the year mixed with periods of normal sleep-wake cycles. Kleine-Levin syndrome is the most well-known form of recurrent hypersomnia, though it is very rare; sufferers often sleep up to eighteen hours a day and yet do not feel refreshed upon waking.
Hypersomnia can be caused by brain damage and disorders such as clinical depression, Celiac Disease, uremia and fibromyalgia. Hypersomnia can also be a symptom of other sleep disorders such as narcolepsy, sleep apnea, restless leg syndrome and periodic limb movement disorder. It may also occur as an adverse effect of taking certain medications (e.g. some psychotropics for depression, anxiety, or bipolar disorder), of withdrawal from some medications, or of drug or alcohol abuse. A genetic predisposition may be a factor.
People who are overweight may be more likely to suffer from hypersomnia. Although studies have shown a correlation between a lack of sleep and weight gain, sleeping at the level of a hypersomniac can also lead to considerable weight gain. This is because excessive sleeping decreases metabolic energy consumption, making weight loss more difficult. Sleep disorders of this nature provoke or initiate weight gain due to a tendency to attempt to manage low energy levels by eating carbohydrates.
Another possible cause is an infection of mononucleosis, as several instances of hypersomnia have been found to arise immediately after such an infection. It can also be caused in children by influenza.
Two people with excessive daytime sleepiness and prolonged nocturnal sleep were treated for their subclinical hypothyroidism, effecting significantly decreased sleep time and daytime sleepiness.
When the cause of the hypersomnia cannot be determined, it is considered to be idiopathic hypersomnia.
Hypersomnia is an uncommon disorder; less than 5% of adults complain of EDS. The disorder usually occurs between ages 15–30 and develops slowly over a period of years.
To be diagnosed with hypersomnia, one must display symptoms for at least a month and the disorder must have a significant impact on the patient's life. The diagnosis is not given if the hypersomnia is a result of medication or of another disorder.
From the website of the US National Institute of Neurological Disorders and Stroke:
- Treatment is symptomatic in nature. Stimulants, such as amphetamine, methylphenidate, and modafinil, may be prescribed. Other drugs used to treat hypersomnia include clonidine, levodopa, bromocriptine, antidepressants, and monoamine oxidase inhibitors. Changes in behavior (for example avoiding night work and social activities that delay bed time) and diet may offer some relief. Patients should avoid alcohol and caffeine.
These drug therapies may or may not work; hypersomnia is a lifelong disorder and recent research theorizes to treat the hypothalamus as a probable solution.