Sleep disorders, also sometimes called sleep-wake disorders, are characterized by problems with the quality, timing, and amount of sleep, which can cause stress and reduced functioning. Sleep disorders can be associated with both physical and mental health problems, and can also worsen pre-existing conditions.
There are more than 100 sleep disorders that have been identified. The four most common sleep disorders include:
- Insomnia
- The most common type of sleep disorder that involves problems falling asleep or staying asleep despite adequate opportunity to do so
- Three types:
- Short-term insomnia disorder
- Chronic insomnia disorder
- Other insomnia disorder (symptoms that do not meet criteria for the other two types of insomnia)
- Narcolepsy
- Excessive daytime sleepiness combined with sudden muscle weakness
- A type of central disorder of hypersomnolence
- Characterized by a primary complaint of daytime sleepiness that is not due to another sleep disorder
- Restless legs syndrome (RLS)
- Characterized by an unpleasant “creeping” sensation, that usually feels as if it originates in the lower legs, and is often associated with aches and pains throughout the legs
- Causes difficulty falling asleep and is relieved by leg movements, such as walking or kicking
- A type of sleep-related movement disorder
- Characterized by movements that disturb sleep
- Patients may or may not be aware of these movements
- Sleep apnea
- Two main types:
- Central sleep apnea syndrome
- Obstructive sleep apnea (OSA) disorder
- A type of sleep-related breathing disorder
- Characterized by abnormal breathing during sleep
- Snoring may be normal or abnormal
- Two main types:
What Are Symptoms of the 4 Most Common Sleep Disorders?
Symptoms of sleep disorders depend on the specific disorder.
Symptoms of insomnia include:
- Difficulty falling asleep or staying asleep
- Variable sleep
- Daytime fatigue or sleepiness
- Forgetfulness
- Inability to concentrate
- Irritability
- Anxiety
- Depression
- Decreased motivation or energy
- Increased errors or accidents
- Persistent worry about sleep
Symptoms of central disorders of hypersomnolence such as narcolepsy include:
- Excessive daytime sleepiness (EDS)
- Sudden muscle weakness (cataplexy)
- Transitioning from being awake to being asleep (hypnagogic hallucinations)
- Frequent short naps during the day
- Difficulty sleeping at night
- Night-time compulsive behaviors such as eating and nocturnal smoking
- Obesity
Symptoms of sleep-related movement disorders such as restless legs syndrome include:
- Overwhelming urge to move your legs
- Itchy, crawling, burning, creepy, throbbing sensation in the legs
- Trouble sitting still for long periods of time
- Daytime sleepiness
- Irritability
- Depression
- Anxiety
- Memory problems
- Short attention span
- Fatigue
Symptoms of sleep-related breathing disorders such as sleep apnea include:
- Morning headache
- Loud snoring
- Fatigue
- Daytime sleepiness
- Restless sleep
- Awakening with choking, gasping, or smothering
- Dry mouth or sore throat
- Frequently waking to urinate
- Awakening unrested, groggy
- Low energy
- Difficulty concentrating
- Memory problems
- Dry mouth or sore throat
What Causes the 4 Most Common Sleep Disorders?
The causes of the various sleep disorders vary.
Causes of insomnia include:
- Changes in sleeping environment (temperature, light, noise)
- Stress: loss of a loved one, loss of a pet, divorce, or job loss
- Recent illness, surgery, or pain
- Use of or withdrawal from stimulants (caffeine), some medications, illegal drugs, or alcohol
- Jet lag
- Shift work
- Mental health problems, such as depression, anxiety, and post-traumatic stress disorder
- Illnesses, especially those that cause pain, stress, or difficulty breathing
- Neurological disorders, such as Parkinson disease and Alzheimer's disease
- Other sleep disorders
- Irregular sleep habits
- Genetics
- May not have a known cause
Causes of and triggers for central disorders of hypersomnolence such as narcolepsy include:
- Unknown in some cases
- Genetics
- Hormonal changes, such as during puberty or menopause
- Significant psychological stressors
- Sudden changes in sleep patterns
- Infection, such as swine flu or a streptococcal infection
- Autoimmune disorder
- Head injury
- Brain tumor
- Multiple sclerosis (MS)
- Encephalitis
Causes of and risk factors for sleep-related breathing disorders such as sleep apnea include:
- Increasing age: more common in middle and older age adults
- Male sex: two times more common in men than in women
- Obesity
- Sedation from medication or alcohol
- Airway abnormality
Causes of sleep-related movement disorders such as restless legs syndrome include:
- Low iron levels
- Diabetes
- Pregnancy
- Certain medications
- Spinal cord injury
- Multiple system atrophy (a rare neurological disorder)
- Sleep related eating disorder (SRED)
How Are the 4 Most Common Sleep Disorders Diagnosed?
Sleep disorders are diagnosed with a patient history and physical exam. Tests or procedures that may be used to diagnose sleep disorders or to rule out other underlying conditions include:
- Daily sleep log
- Sleep study (polysomnography)
- Record of activity and movement with a monitor or motion detector, generally worn on the wrist throughout the day and night (actigraphy)
- Home sleep apnea testing
- Home devices that monitor breathing, oxygen saturation, position, and heart rate
- Melatonin sampling
- Core body temperature measurements
- Hormone tests
- Electrocardiogram (“ECG”)
- Computerized tomography (CT) scan
- Pulmonary function tests
- Magnetic resonance imaging (MRI) of the brain
What Is the Treatment for the 4 Most Common Sleep Disorders?
Treatment for insomnia includes:
- Cognitive behavioral therapy for insomnia (CBT-I)
- Sleep education
- Sleep restriction or sleep compression
- Stimulus control
- Sleep hygiene
- Relaxation exercises
- Sleep medications, both over-the-counter (OTC) and prescription
Treatment for central disorders of hypersomnolence such as narcolepsy includes:
- Behavioral changes
- Medications:
- Stimulants
- Medications to treat cataplexy
- Histamine H3 antagonists/inverse agonists
Treatment for sleep-related breathing disorders such as sleep apnea includes:
- Continuous positive airway pressure (CPAP)
- Adjusting sleep position (to stay off the back)
- Weight loss
- Avoiding alcohol and other sedatives
- Dental devices
- Surgery
Treatment for sleep-related movement disorders such as restless legs syndrome includes:
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https://www.psychiatry.org/patients-families/sleep-disorders/what-are-sleep-disorders
https://www.uptodate.com/contents/classification-of-sleep-disorders?search=sleep%20disorders&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
https://www.uptodate.com/contents/insomnia-beyond-the-basics?search=insomnia&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=3
https://www.uptodate.com/contents/insomnia-treatments-beyond-the-basics?search=insomnia&topicRef=7717&source=see_link
https://www.uptodate.com/contents/sleep-apnea-in-adults-beyond-the-basics?search=sleep%20apnea&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=3#H4
https://www.uptodate.com/contents/narcolepsy-the-basics?search=narcolepsy&source=search_result&selectedTitle=1~118&usage_type=default&display_rank=1
https://www.nhlbi.nih.gov/health-topics/circadian-rhythm-disorders
http://www.sleepallies.org/circadian_rhythm_sleep-wake_di.php
http://sleepeducation.org/essentials-in-sleep
https://www.cdc.gov/sleep/about_sleep/key_disorders.html