Sleep Disorders: Types, Symptoms, and Treatments

By Ashley Little

Apr 15th, 2021

According to the National Sleep Foundation, it’s believed that 50 to 70 million Americans suffer from some type of sleep disorder. 

A sleep disorder – technically known as a somnipathy or dyssomnia – is any medical disorder which negatively affects a person’s healthy sleep patterns. Usually this involves less than adequate sleep to the extent that this may interfere with the person’s normal physical, mental and emotional functioning, but excessive sleep (such as in hypersomnia and narcolepsy) can also be a problem.

There are more than 80 types of sleep disorders that fall into one of seven categories including, insomnias, sleep-related breathing disorders, sleep-related movement disorders, sleep-wake disorders, hypersomnias, and parasomnias.

Browse all of our resources that deep dive into the various types of sleep disorders, how to recognize the symptoms, what to do if you think you have a sleep disorder, and treatment options.

Understanding Sleep Disorders

Sleep disorders are fairly common and they have a variety of causes including mental illness, physical health conditions, medications, genetics, irregular sleep schedules (i.e. shift workers), and aging. Not to mention the hidden list of unknown causes that researchers are still working to uncover.

In some cases, individuals don’t even realize they have a sleep disorder and it takes their bed partner, who recognizes abnormal sleep behavior, to point them out. Yet, there are a number of signals one can observe in themselves that indicate they suffer from some kind of sleep disorder. 

The most blatant symptom that you have a sleep disorder is being constantly tired as a result of little sleep, failing to fall asleep easily, frequent interruptions during sleep, and overall poor quality of sleep. 

If you believe you may have a sleep disorder, the first step is to discuss your observations and concerns with a physician. Recognizing the common signs of a sleep disorder can help you catch a potential issue quickly.

See our resources below to learn more about the causes, symptoms, and diagnosis of sleep disorders.

Diagnosing a Sleep Disorder

Typically, sufferers may complain of difficulty getting to sleep, difficulty staying asleep, intermittent wakefulness during the night, early morning awakening, or combinations of any or all of these. 

It should be noted that the vast majority of those afflicted with sleep disorders (even some of the more garish and extreme ones) are not suffering from unaddressed psychological problems as was once assumed, but have healthy psychological profiles similar to the rest of the population.

Sleep problems are a notoriously common issue, and researchers are constantly working to better understand the causes. In one recent study, nearly 60% of Americans complained of insomnia symptoms a few nights of the week or more, and up to 20% may be affected by chronic sleep disorders. 

Another study, more commonly quoted, indicates that 30%-40% of adults suffer from some degree of sleep loss in any given year, with about 10%-15% categorized as chronic or severe. It should also be noted, though, that sleep state misperception is quite common, and often people actually sleep significantly longer than they think. On the other hand, many sleep disorders are notoriously difficult to diagnose and are often mis-diagnosed.

Types of Sleep Disorders

There are numerous types of sleep disorders that fall into one of six categories; however, oftentimes different disorders can be closely related. The most common types of sleep disorders in American adults are insomnia and obstructive sleep apnea.

The six types of sleep disorders we’ll review below include: 


Insomnia is defined by difficulty falling or staying asleep and is one of the most common sleep disorders across the US population, affecting roughly 40% of adults at some point in their lives.  

There are two categories of insomnia: primary and secondary. Primary insomnia means experiencing sleep problems unrelated to any other health condition or life circumstance. Secondary insomnia means experiencing sleep issues as a result of something else.

Insomnia also varies in the length of time it lasts and the frequency that someone experiences it. In some cases, people have insomnia for a short period of time (acute insomnia). Other times, individuals may experience insomnia in the long-term (chronic insomnia).

Learn more about the symptoms, causes, types and treatment for insomnia in our resources below.

Sleep Apnea, Snoring, and Other Breathing Disorders

Sleep-related breathing disorders, also called sleep-disordered breathing, are defined by abnormal respiration during sleep. The most common sleep-related breathing disorder is sleep apnea.  

Twenty-five million American adults suffer from obstructive sleep apnea and half the population reports snoring, which is a habit our culture tends to laugh about but in reality, it can be a sign of a larger health problem. 

Learn more about specific sleep-related breathing disorders in our resources below.

Circadian Rhythm Sleep-Wake Disorders

Sleep-wake disorders, also known as circadian rhythm disorders, are experienced when the body’s internal clock (circadian rhythm) is out of sync with the surrounding environment. 

In other words, people with this type of sleep disorder fail to fall asleep and wake up at appropriate times— i.e. sleep during the day and stay awake at night. Some of the most common sleep-wake disorders are jet lag disorder, shift-work sleep disorder, delayed sleep phase disorder (DSP), and advanced sleep phase disorder (ASP). 

Learn more about sleep-wake sleep disorders in our resources below.


Hypersomnia, sometimes referred to as excessive daytime sleepiness (EDS) disorder, is a sleep condition in which you feel excessive sleepiness during the day even if you have logged an adequate amount of shut eye the night before. You can think of hypersomnia as the opposite of insomnia. 

Similar to insomnia, hypersomnia can be a primary or secondary condition. People who suffer from chronic tiredness caused by hypersomnia often have difficulty functioning during the day due to a lack of concentration and energy. 

Learn more about hypersomnia types and treatments in our resources below.


Parasomnia is the word used to categorize abnormal behavior that can take place during sleep. Some of the parasomnias you’ll be most familiar with are nightmares and sleepwalking. 

However, there are a number of other parasomnias you may not have heard of, such as, sexsomnia, sleep paralysis, and sleep-related eating disorder. Ten percent of the population is affected by this type of sleep disorder and it’s most likely linked to genetics. 

Learn more about different types and treatments for parasomnias in our resources below.

Movement-Related Sleep Disorders

Sleep-related movement disorders are characterized by abnormal movements that take place while falling asleep or during sleep itself. The most common sleep disorders of this kind are teeth grinding, also known as bruxism, and restless leg syndrome (RLS). 

It’s estimated that one in ten adults have RLS and roughly 15 percent of children are known to grind their teeth in their sleep. In most cases, this type of sleep disorder resolves itself. 

Learn more about the different types of sleep-related movement disorders in our resources below. 

Other Sleep Disorders

A few other minor sleep disorders and conditions affecting sleep are worth mentioning, including:

  • Nocturia or Nycturia, interrupted sleep due to the frequent need to get up to urinate during the night, particularly common in pregnant women and the elderly.
  • Bed-wetting or Enuresis, uncontrolled urination during sleep, especially prevalent in young children, which may be caused by an insufficient supply of the antidiuretic hormone ADH, a small bladder combined with long sleep periods, or other physical or emotional problems.
  • Hypnophobia or Somniphobia, an anxiety disorder manifesting as an abnormal fear of sleeping or going to bed, a psychological state perpetuated by self-induced stress and anxiety (also known as negative sleep conditioning).
  • Nocturnal Dissociative Disorder, a psychiatric disorder of wakefulness , superficially similar to sleep-walking, in which a sufferer wanders off or acts out scenarios while technically awake (although completely unaware of their actions, and with no subsequent memory of them), usually as a psychological response to earlier abuse or trauma.
  • Encephalitis Lethargica, an extremely rare viral infection of the sleep-wake cycle mechanisms in the hypothalamus, causing extreme lethargy, sleep period inversion, even catatonia or a completely unresponsive coma-like state.

Conditions Associated with Sleep Disorders

Many other superficially unconnected medical or psychological conditions have nevertheless been closely linked with sleep problems. It is, however, not always clear where the causal relationship lies: in some cases, the conditions lead to sleep problems; in other cases, the opposite is true, and long-term sleep disorders can actually cause the conditions; occasionally, both may occur, in a spiral of positive reinforcement.

Some or the better-known diseases and conditions that fall into this category include the following:

  • Alzheimer’s disease (AD), and other kinds of dementia, which in their early stages may be characterized by excessive sleeping (hypersomnia), and in their later stages may be marked by insufficient sleep or insomnia, with nighttime sleep being ultimately replaced by short irregular dozes throughout the day and night more reminiscent of irregular sleep-wake rhythm disorder (ISWRD) or polyphasic sleep (in dementia patients, the number of neurons in the circadian pacemaker becomes substantially reduced, so that circadian rhythms may be severely disrupted).
  • Anxiety (and other related mood disorders), which typically leads to difficulty falling asleep and staying asleep throughout the night.
  • Asthma, particularly nocturnal asthma, in which asthma symptoms worsen at night, so that coughing, wheezing and breathlessness disrupt sleep.
  • Attention Deficit Hyperactivity Disorder (ADHD), whose incidence and symptoms in children show marked overlaps with those of sleep disorders. Sleep disorders in children are often misdiagnosed as ADHD (and vice versa), and some recent research has also suggested that sleep‘s role in the brain’s consolidation of emotional memories in particular may be linked to ADHD symptoms.
  • Autism Spectrum Disorders (ASD) affect an estimated 1 in 150-160 children, and half to three-quarters of them typically develop sleep disorders of some kind. Others appear to be able to function more or less normally on significantly reduced hours of sleep. Some have theorized that children with autism produce less melatonin in their brains, or do not produce it at normal times, possibly due to genetic mutations (the gene and enzyme ASMT, which is known to be involved in the production of melatonin, has been specifically flagged in this respect). Another possible link stems from iron deficiency, a common problem in autistic children, which may lead to sleep disorders like restless legs syndrome.
  • Depression, which is often accompanied by insomnia or similar symptoms (especially waking up too early in the morning), or sometimes the opposite, hypersomnia-like symptoms. Those suffering from depression tend to experience REM sleep much earlier in their sleep cycles than normal, suggesting some disruption in the drive-regulation function. REM deprivation, by means of antidepressant medication, may fix this sleep stage abnormality, as well as relieving the waking symptoms of depressives. Depression shares many risk factors and biological features with various different sleep disorders, and misdiagnosis is common.
  • Diabetes, specifically type II diabetes, which can be precipitated by sleep deprivation-driven changes in the balance of hormones that regulate appetite, leading to overeating, higher glucose levels and insulin resistance, all of which are risk factors for type II diabetes.
  • Multiple sclerosis (MS), which tends to bring with it a variety of sleep disorders including insomnia, restless legs syndrome, narcolepsy, REM sleep behaviour disorder, and others.
  • Epilepsy, as well as the drugs typically used to treat it, appear to be inherently implicated in sleep disorders. In fact, epilepsy disturbs sleep and sleep deprivation aggravates epilepsy, in a two-way connection. Epilepsy sufferers may or may not have seizures at night depending on the type of epilepsy (for some people, seizures may occur exclusively during sleep), and they are also more prone to sleep apnea.
  • Obesity, which is a major contributing factor to sleep disorders like sleep apnea, but also a common consequence of many sleep disorders, through their effect on metabolism and hormonally-increased appetite.
  • Parkinson’s disease (PD), which has been linked with several sleep disorders, including insomnia, REM sleep behaviour disorder, periodic leg movement disorder, restless legs syndrome, sleep apnea, narcolepsy, etc.
  • Schizophrenia, for which sleep disorders are one of the most common indications (affecting some 30%-80% of patients). An improvement in sleep quality is frequently correlated with an improvement in negative symptoms in schizophrenics.
  • Seasonal affective disorder (SAD), also known as winter depression, which is triggered by the desynchronization of circadian rhythms during the shorter days of fall and winter.