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The Six Types of Sleep Disorders

A woman sitting on her bed awake because of a sleep disorder.

Chronic snoring, tossing-and-turning and nightmares leave many yawning and desperate for relief the next day—without realizing these symptoms are part of the six classes of sleep disorders.

About 50 to 70 million U.S. adults have a sleep disorder, a family of 90 conditions that affect sleep cycles and depth, according to the National Institutes of Health.

Cedars-Sinai pulmonologist and sleep medicine expert, Oragun Rojanapairat, MD.

Oragun Rojanapairat, MD

"If you're going to bed at a reasonable time for your schedule and still waking up exhausted most days, don't assume your sleep issue will disappear without finding and addressing the cause," says Dr. Oragun Rojanapairat, Cedars-Sinai pulmonologist and sleep medicine expert. "Most patients wait until long after they start struggling to seek help."

Sleep disturbances can seriously impair functioning and health. Adults need seven to eight hours of shut-eye each day: If you don't get enough sleep, memory, focus, mood, strength and even the immune system may suffer. 


"If you're going to bed at a reasonable time for your schedule and still waking up exhausted most days, don't assume your sleep issue will disappear without finding and addressing the cause."


Over time, sleep deprivation can lead to obesity, diabetes, high blood pressure, heart disease, stroke and poor mental health. 

A sleep specialist can help diagnose your sleep disorder using an in-depth assessment or sleep study and offer tailored care plans that improve quality of life.

Here's a look at the six categories of sleep disorders and how you can get better rest.

1. Lack of sleep

Insomnia sufferers have a hard time falling or staying asleep and often feel drowsy. Among the most common conditions, about 33% to 50% of adults have some insomnia symptoms, according to the American Academy of Sleep Medicine. 

Insomnia often spikes during stress but can become chronic if symptoms last for three months or longer. Poor sleep habits, environmental changes, medications and co-occurring medical conditions such as asthma or sleep apnea can all aggravate the problem. 

The leading treatment is cognitive behavioral therapy for insomnia, which coaches a patient on sleep cycles and personal sleep barriers. Providers may also prescribe supplementary medications. 



2. Snoring and sleep apnea

Snoring is frustrating—but it can also be dangerous. 

More than 20 million Americans have sleep apnea. The frequent choking and breathing interruptions—at least 5 times an hour—affect sleep quality and oxygen levels. Without treatment, it's tied to high blood pressure, heart disease and stroke. 

The gold standard of care, continuous positive airway pressure therapy, or CPAP, facilitates airflow. Other options move the lower jaw and tongue forward (with a mandibular advancement device and nerve stimulator) to prevent airway collapse. Patients might also benefit from surgery on excess nose and throat tissue that interferes with breathing.



3. Circadian rhythm disorders

"Lark" and "night owl" tendencies are biologically wired—caused by advanced (early riser) or delayed (late sleeper) sleep-wake phase disorders. Both run on an internal clock (circadian rhythm) different from the outside day-night cycle.

While many people make this quirk work, it becomes problematic when it affects functioning during the time you want to be awake, Dr. Rojanapairat explains. 

Traveling across two or more time zones (jet lag) or working overnight (shift work disorder) can also throw off rhythms.

A body clock that's out of balance with your schedule may trigger insomnia or repeated waking at times that don't allow a full seven to eight hours of sleep, leading to sleepiness and focus and mood problems.

Treatment is aimed at creating brain cues for rest and wakefulness: a tiny (.5 milligram) dose of melatonin and bright light exposure. Use lights and healthy sleep hygiene—a consistent routine and avoiding electronics before bed—to help shift your cycle and reinforce your preferred schedule.



4. Movement disorders

Restless leg syndrome in the legs and feet makes sitting still at night feel almost impossible.

Certain health conditions and medications—including kidney disease, iron deficiency, neuropathy, pregnancy, anxiety and antidepressants—can bring on these uncomfortable or painful urges, which happen to about 7% to 10% of people.

Doctors may cut out contributing drugs and supplement iron, if needed. They may also prescribe symptomatic relief through medication, foot wraps and other aids.



5. Parasomnias

These uncontrollable sleep episodes include sleepwalking, sleep talking, hallucinations, sleep paralysis and night terrors the person doesn't remember afterward.

Some parasomnias such as nightmares can be set off by post-traumatic stress or sleep deprivation.

Since they're more common in kids, many people outgrow them, Dr. Rojanapairat says, but providers often try to reduce the risk of injury and resolve any triggers.

6. Too much sleep

Unlike most other sleep disorders, people with hypersomnias often oversleep (over 10 hours a night)—but still feel groggy no matter how early they go to bed. They might have sleep attacks or hallucinations.

Narcolepsy, a nervous system disorder caused by a lack of orexin brain chemicals, has an added symptom: sudden-onset muscle weakness (cataplexy) that gets worse with strong emotions.

Sleep deprivation mimics some of these, Dr. Rojanapairat cautions—but gets better with rest.

Providers will conduct a nap study and treat hypersomnias with a mixture of sleep hygiene, napping, driving safety and stimulant medications.

Don't suffer needlessly trying to shake off fatigue on your own. Worrying about sleep or trying to self-medicate often backfires. If you're having ongoing concerns, your primary care doctor can refer you to a sleep specialist, or you can self-refer for a full assessment.