There are two categories of primary sleep disorders: dyssomnias and parasomnias.
Problems with regard to the amount, timing, or quality sleep are grouped together as dyssomnia. Because somnia implies sleep and the prefix dys (or dis) signifies “abnormal” or a “failing” of some sort, dyssomnia indicates a failure to sleep or abnormal sleep. The dyssomnias include primary insomnia (cannot sleep), primary hypersomnia (sleeping too much), breathing-related sleep disorder, sleep apnea, narcolepsy, nocturnal myoclonus (or restless legs syndrome), and circadian rhythm difficulties.
Primary Insomnia – This disorder manifests as difficulty in sleeping that lasts for at least 30 days. The problem may be either in falling asleep or in staying asleep once a person has fallen asleep.
Primary Hypersomnia – This disorder presents as excessive sleepiness for at least 30 days. It can be manifested by prolonged nighttime sleep or by multiple episodes of daytime sleep.
Sleep Apnea – A cessation of breathing with resultant oxygen deprivation is the chief symptom of this disorder, and it may happen hundreds of times per night, with cessations of up to 10 or more seconds or even a few minutes.
There are two types of sleep apnea.
Obstructive Sleep Apnea is caused by blockage from collapse of airways required for breathing. Snoring can be a sign of partial collapse and a forewarning of apnea (but perhaps years down the road); obesity can be a contributing factor.
The other form of apnea is called Central Alveolar Hypoventilation Syndrome and reflects a problem with the respiratory drive, which has decreased greatly or even stopped. Snoring is not a symptom of the central form, and patients tend more toward insomnia than hypersomnia (which is opposite from those with obstructive sleep apnea).
Some patients demonstrate both forms of apnea and are diagnosed with Mixed Sleep Apnea.
Nocturnal Myoclonus – This disorder is better known as Restless Legs Syndrome and is characterized by either sudden muscular contractions or almost indescribable, strange tingly feelings in one’s legs. Patients may describe these sensations as “spiders walking around inside my legs” or “something that makes me get up and move.” This difficulty becomes Nocturnal Myoclonus when it seriously interferes with sleep.
Narcolepsy – The sudden and repeated onset of sleep is the most common indication of narcolepsy. The deep sleep that occurs, as well as its inception, seems uncontrollable to the patient, who will involuntarily fall asleep at inappropriate times. Narcolepsy can prove disabling and may include hallucinations and/or brief episodes of paralysis.
Circadian Rhythm Difficulty – This is a sleep problem relating to the 24-hour (clock) cycle by which most individuals live their lives and schedule their activities, including sleep. It occurs, usually temporarily, when a person changes her body’s schedule of activities for work, travel, or other purposes. Examples are jet lag (a result of long distance air travel) and shift work sleep problems.
Parasomnias are troublesome events that happen during sleep or semi-sleep states, but they do not always affect the quality or quantity of one’s sleep. The prefix of the term (para) denotes a partial sleep, because most of these events take place during partial arousal or partial sleep states. Several examples of parasomnia are sleepwalking (somnambulism), sleep talking (somniloquy), sleep eating, sleep driving, nightmares, night terrors, and bedwetting.
Recommended treatment varies, depending on the sleep problem or disorder, and includes, but is not limited to, the following:
weight loss (especially for sleep apnea)
enhanced respiratory ventilation (such as use of the positive airway pressure or PAP machine or the continuous positive airway pressure or CPAP machine for sleep apnea)
medications (e.g., stimulants, stimulating antidepressants, estrogen, MAOIs, and benzodiazephines)
regimen of good sleep hygiene/habits