The causes of sleep disorders can vary depending on the condition. The causes of some specific sleep disorders are discussed below.
- Delayed sleep phase syndrome (DSPS): This sleep disorder is caused by an abnormality in the patient’s circadian rhythm and not any external factors such as jet lag or working late or irregular hours.
- Insomnia: Insomnia has many potential causes, including psychological disorders such as stress, anxiety and bipolar disorder, and health conditions such as arthritis, overactive thyroid glands, gastrointestinal disorders, Alzheimer’s disease, Parkinson’s disease, sleep apnea and restless legs syndrome. In addition, taking certain medications, consuming caffeine, jet lag, sleep pattern disturbances, excessive day-sleeping, and physical or intellectual stimulation before bed may cause insomnia.
- Narcolepsy: Scientists are not entirely sure what causes this particular sleep disorder. Genetics is thought to play a role, but only 2 percent of narcolepsy patients have a family history, so other factors are likely involved. These patients have imbalances in brain chemicals that control sleep, though the ultimate cause of these imbalances is not always known.
- Night terrors: There are many factors that can cause night terrors, including fatigue, stress, illnesses (especially illnesses that cause fevers), and medication that affect the brain or spinal cord.
- REM sleep behavior disorder (RBD): As with narcolepsy, the causes of RBD are unknown. This disorder has, however, been linked to degenerative neurological disorders such as Parkinson’s disease, though not all patients with RBD will develop neurological disorders. Individuals withdrawing from alcohol or sedative-hypnotic drugs (e.g., Ambien, Lunesta and Sonata) may have a temporary form of this condition, which will eventually go away.
- Sleep apnea: Obstructive sleep apnea, the most common form of the condition, occurs when the throat muscles that control the soft palate, tonsils and tongue relax, causing an inability to breathe, which then prompts the brain to react by waking the individual up. This process can occur 20 to 30 times an hour during sleep, usually without the patient’s awareness. This happens most often in older adults, especially men; obese individuals are at increased risk as well, because they have excess fat in their upper airways. The other form, central sleep apnea, occurs when the brain does not send proper signals to the muscles that control breathing during sleep. Central sleep apnea is usually caused by heart disease, and these patients are more likely to remember waking up. In addition, as many as 15 percent of sleep apnea patients will have what’s called complex sleep apnea, which is a combination of obstructive and central sleep apneas. It affects males and females equally, and can develop at any age.