Over the past thirty years, several studies have found that those afflicted with NSRED all have different symptoms and behaviors specific to them, yet they also all have similar characteristics that doctors and psychologists have identified to distinguish NSRED from other combinations of sleep and eating disorders such as night eating syndrome. Winkelman says that typical behaviors for patients with NSRED include: "Partial arousals from sleep, usually within 2 to 3 hours of sleep onset, and subsequent ingestion of food in a rapid or 'out of control' manner." They also will attempt to eat bizarre amalgamations of foods and even potentially harmful substances such as glue, wood, or other toxic materials. In addition, Schenck and Mahowald noted that their patients mainly ate sweets, pastas, both hot and cold meals, improper substances such as "raw, frozen, or spoiled foods; salt or sugar sandwiches; buttered cigarettes; and odd mixtures prepared in a blender."

During the handling of this food, patients with NSRED distinguish themselves, as they are usually messy or harmful to themselves. Some eat their food with their bare hands while others attempt to eat it with utensils. This occasionally results in injuries to the person as well as other injuries. After completing their studies, Schenck and Mahowald said, "Injuries resulted from the careless cutting of food or opening of cans; consumption of scalding fluids (coffee) or solids (hot oatmeal); and frenzied running into walls, kitchen counters, and furniture." A few of the more notable symptoms of this disorder include large amounts of weight gain over short periods of time, particularly in women; irritability during the day, due to lack of restful sleep; and vivid dreams at night. It is easily distinguished from regular sleepwalking by the typical behavioral sequence consisting of "rapid, 'automatic' arising from bed, and immediate entry into the kitchen." In addition, throughout all of the studies done, doctors and psychiatrists discovered that these symptoms are invariant across weekdays, weekends, and vacations as well as the eating excursions being erratically spread throughout a sleep cycle. Most people that suffer from this disease retain no control over when they arise and consume food in their sleep. Although some have been able to restrain themselves from indulging in their unconscious appetites, some have not and must turn to alternative methods of stopping this disorder. It is important for trained physicians to recognize these symptoms in their patients as quickly as possible, so those with NSRED may be treated before they injure themselves.

Nocturnal sleep-related eating disorder (NSRED), also known as sleep-related eating disorder (SRED), sleep eating, or somnambulistic eating, is a combination of a parasomnia and an eating disorder. It is described as being in a specific category within somnambulism or a state of sleepwalking that includes behaviors connected to a person's conscious wishes or wants. Thus many times NSRED is a person's fulfilling of their conscious wants that they suppress; however, this disorder is difficult to distinguish from other similar types of disorders.

NSRED is closely related to night eating syndrome (NES) except for the fact that those suffering from NES are completely awake and aware of their eating and bingeing at night while those suffering from NSRED are sleeping and unaware of what they are doing. NES is primarily considered an eating disorder while NSRED is primarily considered a parasomnia; however, both are a combination of parasomnia and eating disorders since those suffering from NES usually have insomnia or difficulty sleeping and those suffering from NSRED experience symptoms similar to binge eating. Some even argue over whether NES and NSRED are the same or distinct disorders. Even though there have been debates over these two disorders, specialists have examined them to try to determine the differences. Dr. J. Winkelman noted several features of the two disorders that were similar, but he gave one important factor that make these disorders different. In his article "Sleep-Related Eating Disorder and Night Eating Syndrome: Sleep Disorders, Eating Disorders, Or both", Winkelman said, "Both [disorders] involve nearly nightly binging at multiple nocturnal awakenings, defined as excess calorie intake or loss of control over consumption." He also reported that both disorders have a common occurrence of approximately one to five percent of adults, have been predominantly found in women, with a young adult onset, have a chronic course, have a primary morbidity of weight gain, sleep disruption, and shame over loss of control over food intake, have familial bases, and have been observed to have comorbid depression and daytime eating disorders. However, Winkelman said, "The most prominent cited distinction between NES and SRED is the level of consciousness during nighttime eating episodes." Therefore, these two disorders are extremely similar with only one distinction between them. Doctors and psychologists have difficulty differentiating between NES and NSRED, but the distinction of a person's level of consciousness is what doctors chiefly rely on to make a diagnosis. One mistake that is often made is the misdiagnosis of NSRED for NES. However, even though NSRED is not a commonly known and diagnosed disease, many people suffer from it in differing ways while doctors work to find a treatment that works for everyone; several studies have been done on NSRED, such as the one conducted by Schenck and Mahowald. These studies, in turn, provide the basic information on this disorder including the symptoms, behaviors, and possible treatments that doctors are using today.

NES is sometimes comorbid with excess weight; as many as 28% of individuals seeking gastric bypass surgery were found to suffer from NES in one study. However, not all individuals with NES are overweight. Night eating has been associated with diabetic complications. Many people with NES also experience depressed mood and anxiety disorders.

Night eating syndrome (NES) is an eating disorder, characterized by a delayed circadian pattern of food intake. Although there is some degree of comorbidity with binge eating disorder, it differs from binge eating in that the amount of food consumed in the evening/night is not necessarily objectively large nor is a loss of control over food intake required. It was originally described by Dr. Albert Stunkard in 1955 and is currently included in the other specified feeding or eating disorder category of the DSM-5. Research diagnostic criteria have been proposed and include evening hyperphagia (consumption of 25% or more of the total daily calories after the evening meal) and/or nocturnal awakening and ingestion of food two or more times per week. The person must have awareness of the night eating to differentiate it from the parasomnia sleep-related eating disorder (SRED). Three of five associated symptoms must also be present: lack of appetite in the morning, urges to eat in the evening/at night, belief that one must eat in order to fall back to sleep at night, depressed mood, and/or difficulty sleeping.

NES affects both men and women, between 1 and 2% of the general population, and approximately 10% of obese individuals. The age of onset is typically in early adulthood (spanning from late teenage years to late twenties) and is often long-lasting, with children rarely reporting NES. People with NES have been shown to have higher scores for depression and low self-esteem, and it has been demonstrated that nocturnal levels of the hormones melatonin and leptin are decreased. The relationship between NES and the parasomnia SRED is in need of further clarification. There is debate as to whether these should be viewed as separate diseases, or part of a continuum. Consuming foods containing serotonin has been suggested to aid in the treatment of NES, but other research indicates that diet by itself cannot appreciably raise serotonin levels in the brain. A few foods (for example, bananas) contain serotonin, but they do not affect brain serotonin levels, and various foods contain tryptophan, but the extent to which they affect brain serotonin levels must be further explored scientifically before conclusions can be drawn, and "the idea, common in popular culture, that a high-protein food such as turkey will raise brain tryptophan and serotonin is, unfortunately, false."

The universal feature of night terrors is inconsolability, very similar to that of a panic attack. During night terror bouts, people are usually described as "bolting upright" with their eyes wide open and a look of fear and panic on their faces. They will often scream. Furthermore, they will usually sweat, exhibit rapid breathing, and have a rapid heart rate (autonomic signs). In some cases, individuals are likely to have even more elaborate motor activity, such as a thrashing of limbs—which may include punching, swinging, or fleeing motions. There is a sense that the individuals are trying to protect themselves and/or escape from a possible threat of bodily injury. Although people may seem to be awake during a night terror, they will appear confused, be inconsolable and/or unresponsive to attempts to communicate with them, and may not recognize others familiar to them. Occasionally, when a person with a night terror is awakened, they will lash out at the one awakening them, which can be dangerous to that individual. Most people who experience this do not remember the incident the next day. Sleepwalking is also common during night terror bouts, as sleepwalking and night terrors are different manifestations of the same parasomnia.

During lab tests, subjects are known to have very high voltages of electroencephalography (EEG) delta activity, an increase in muscle tone, and a doubled increase in heart rate, if not more. Brain activities during a typical episode show theta and alpha activity when using an EEG. It is also common to see abrupt arousal from NREM sleep that does not progress into a full episode of a night terror. These episodes can include tachycardia. Night terrors are also associated with intense autonomic discharge of tachypnea, flushing, diaphoresis, and mydriasis – that is, unconscious or involuntary rapid breathing, reddening of the skin, profuse sweating, and dilation of the pupils.

In children with night terrors, there is no increased occurrence of psychiatric diagnoses. However, in adults who suffer from night terrors there is a close association with psychopathology or mental disorders. There may be an increased occurrence of night terrors—particularly among those suffering or having suffered from post-traumatic stress disorder (PTSD) and generalized anxiety disorder (GAD). It is also likely that some personality disorders may occur in individuals with night terrors, such as dependent, schizoid, and borderline personality disorders. There have been some symptoms of depression and anxiety that have increased in individuals that have suffered from frequent night terrors. Low blood sugar is associated with both pediatric and adult night terrors. A study of adults with thalamic lesions of the brain and brainstem have been occasionally associated with night terrors. Night terrors are closely linked to sleepwalking and frontal lobe epilepsy.

Symptoms reported by patients forced into a 24-hour schedule are similar to those of sleep deprivation and can include:

- Apraxia including ideational apraxia, ideomotor apraxia, kinetic apraxia, limb apraxia, verbal apraxia

- Cognitive dysfunction

- Difficulties concentrating

- Confusion

- Depressed mood

- Diarrhea

- Extreme nausea

- Extreme fatigue

- Hair loss

- Headaches

- Impaired balance

- Photosensitivity

- Joint pain

- Loss of muscle coordination (ataxia)

- Menstrual irregularities

- Muscle pain

- Suicidal thoughts

- Weight gain

- Hallucinations

Parasomnia disorders are classified into the following categories:

- arousal disorders

- sleep-wake transition disorders

- parasomnias associated with REM sleep

Under DSM-5 criteria, there are 11 diagnostic groups that comprise sleep-wake disorders. These include, Insomnia disorder, Hypersomnolence disorder, Narcolepsy, Obstructive sleep apnea hypopnea, Central sleep apnea, Sleep-related hypoventilation, Circadian rhythm sleep-wake disorders, Non–rapid eye movement (NREM) sleep arousal disorders, Nightmare disorder, Rapid eye movement (REM) sleep behavior disorder, Restless legs syndrome, and substance-medication-induced sleep disorder. Sexsomnia is classified under NREM arousal parasomnia.

Exercise Bulimia can sometimes go unnoticed because exercise is something that is seen as healthy, but just because a person looks healthy does not mean they are. Compulsive exercisers will often schedule their lives around exercise just as those with eating disorders schedule their lives around eating (or not eating). Other indications of compulsive exercise are:

- Missing work, school and other important events in order to work out

- Working out with an injury or while sick

- Working out secretly or away from noticeable sight

- Becoming unusually depressed if unable to exercise

- Working out for hours at a time each day

- Not taking any rest or recovery days

- Defining self-worth in terms of performance

- Justifies excessive behavior by defining self as a "special" elite athlete

- Depression or agitation when unable to work out

- Amenorrhea, the stop of a woman's menstrual cycle

- Isolation from others while working out

- Lack of interest in friends and eating

- Lack of sleep

Night terrors in adults have been reported in all age ranges. Though the symptoms of night terrors in adolescents and adults are similar, the cause, prognosis and treatment are qualitatively different. These night terrors can occur each night if the sufferer does not eat a proper diet, get the appropriate amount or quality of sleep (e.g. sleep apnea), is enduring stressful events, or if he or she remains untreated. Adult night terrors are much less common, and often respond to treatments to rectify causes of poor quality or quantity of sleep. Night terrors are classified as a mental and behavioral disorder in the ICD. A study done about night terrors in adults showed that other psychiatric symptoms were prevalent in most patients experiencing night terrors hinting at the comorbidity of the two. There is some evidence of a link between night terrors and hypoglycemia.

When a night terror happens, it is typical for a person to wake up screaming and kicking and to be able to recognize what he or she is saying. The person may even run out of the house (more common among adults) which can then lead to violent actions. It has been found that some adults who have been on a long-term intrathecal clonidine therapy show side effects of night terrors, such as feelings of terror early in the sleep cycle. This is due to the possible alteration of cervical/brain clonidine concentration. In adults, night terrors can be symptomatic of neurological disease and can be further investigated through an MRI procedure.

It has been estimated that non-24 occurs in more than half of all people who are totally blind. The disorder can occur at any age, from birth onwards. It generally follows shortly after loss or removal of a person’s eyes, as the photosensitive ganglion cells in the retina are also removed.

Without light to the retina, the suprachiasmatic nucleus (SCN), located in the hypothalamus, is not cued each day to synchronize the circadian rhythm to the 24-hour social day, resulting in non-24 for many totally blind individuals. Non-24 is rare among visually impaired patients who retain at least some light perception. Researchers have found that even minimal light exposure at night can affect the body clock.

The fifth edition of the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-5) renamed "Feeding Disorder of Infancy or Early Childhood" to Avoidant/Restrictive Food Intake Disorder, and broadened the diagnostic criteria. Previously defined as a disorder exclusive to children and adolescents, the DSM-5 broadened the disorder to include adults who limit their eating and are affected by related physiological or psychological problems, but who do not fall under the definition of another eating disorder.

The DSM-5 defines the following diagnostic criteria:

- Disturbance in eating or feeding, as evidenced by one or more of:

- Substantial weight loss (or, in children, absence of expected weight gain)

- Nutritional deficiency

- Dependence on a feeding tube or dietary supplements

- Significant psychosocial interference

- Disturbance not due to unavailability of food, or to observation of cultural norms

- Disturbance not due to anorexia nervosa or bulimia nervosa, and no evidence of disturbance in experience of body shape or weight

- Disturbance not better explained by another medical condition or mental disorder, or when occurring concurrently with another condition, the disturbance exceeds what is normally caused by that condition

In previous years, the DSM was not inclusive in recognizing all of the challenges associated with feeding and eating disorders in 3 main domains:

- Eating Disorders Not Otherwise Specified (EDNOS) was an all-inclusive, placeholder group for all individuals that presented challenges with feeding

- The category of Feeding Disorder of Infancy/ Early Childhood was noted to be too broad, limiting specification when treating these behaviors

- There are children and youth who present feeding challenges but do not fit within any existing categories to date

Children are often picky eaters, this does not necessarily mean they meet the criteria for an ARFID diagnosis. In addition, self-identification as having ARFID may contribute to ARFID.

Patients with Kleine–Levin syndrome (KLS) experience reoccurring episodes of prolonged sleep (hypersomnia). In most cases, patients sleep 15 to 21 hours a day during episodes.

Excessive appetite (hyperphagia) and unusual cravings are present in half to two thirds of cases. About half of patients, mainly male patients, experience dramatically increased sexual urges (hypersexuality). Several other symptoms usually accompany the syndrome, including marked changes in mood and cognitive ability. Derealization and severe apathy are present in at least 80 percent of cases. About one third of patients experience hallucinations or delusions. Depression and anxiety occur less commonly; one study found them in about 25 percent of patients. Individuals usually cannot remember what happened during episodes. Repetitive behaviors and headaches are commonly reported. Some patients act very childlike during episodes, and communication skills and coordination sometimes suffer.

Sleep studies of KLS show varying results based on the amount of time the patient is observed. Slow wave sleep is often reduced at the beginning of episodes, and REM sleep is reduced near the end. Conversely, REM sleep is often normal at the beginning, and slow wave sleep is often normal by the conclusion. Stage two non-rapid eye movement sleep is often interrupted during KLS. Studies also show that stage one and three non-rapid eye movement sleep become more efficient when the episodes end. The Multiple Sleep Latency Test has yielded inconsistent results when given to KLS patients. In many cases, hours are spent in a withdrawn sleep-like state while awake during episodes. Most sleep studies have been performed while subject are near the end of their episodes. Some patients experience brief insomnia and become very happy and talkative after the episode ends.

The first time a patient experiences KLS, it usually occurs along with symptoms that are similar to those of the flu or encephalitis. In at least 75 percent of cases, symptoms occur after an airway infection or a fever. Viruses observed before the development of the condition include Epstein-Barr virus, varicella zoster virus, herpes zoster virus, Influenza A virus subtypes, and adenovirus. Several days after symptoms first occur, patients become very tired. In cases that occur after an infection, KLS usually starts within three to five days for teenagers and fewer for children. In other cases, alcohol consumption, head injury, or international travel precede symptoms. Lifestyle habits, such as stress, alcohol abuse and lack of sleep and stress, have also been proposed as possible triggers. First episodes of KLS are preceded by a clear event in about 90 percent of cases. Recurrences generally do not have clear triggers; only about 15 percent have a precipitating event.

The condition generally disrupts the social lives and academic or profession obligations of sufferers. Some patients also gain weight during episodes. The most severe cases cause a long-term impact on mood and cognitive attention. In rare cases, patients experience long-term memory problems.

In patients with KLS, MRI and CT scans show normal brain morphology. When SPECT is performed, hypoperfusion can often be observed in the brain, particularly in the thalamic and frontotemporal areas. The hypoperfusion is significantly diminished between episodes. Serum biology, c-reactive proteins and leptins, the hormonal pituitary axis, and protein in the cerebral spinal fluid (CSF) are normal in KLS patients.

The five OSFED examples that can be considered eating disorders include atypical AN, BN (of low frequency and/or limited duration), BED (of low frequency and/or limited duration), purging disorder, and NES. Of note, OSFED is not limited to these five examples, and can include individuals with heterogeneous eating disorder presentations (i.e., OSFED-other). Another term, Unspecified Feeding or Eating Disorder (UFED), is used to describe individuals for whom full diagnostic criteria are not met but the reason remains unspecified or the clinician does not have adequate information to make a more definitive diagnosis.

- Atypical Anorexia Nervosa: In atypical AN, individuals meet all of the criteria for AN, with the exception of the weight criterion: the individual's weight remains within or above the normal range, despite significant weight loss.

- Atypical Bulimia Nervosa: In this sub-threshold version of BN, individuals meet all criteria for BN, with the exception of the frequency criterion: binge eating and inappropriate compensatory behaviors occur, on average, less than once a week and/or for fewer than 3 months.

- Binge-eating disorder (of low frequency and/or limited duration): In this sub-threshold version of BED, individuals must meet all criteria for BED, with the exception of the frequency criterion: binge eating occurs, on average, less than once a week and/or for fewer than 3 months.

- Purging Disorder: In purging disorder, purging behavior aimed to influence weight or shape is present, but in the absence of binge eating.

- Night Eating Syndrome: In NES, individuals have recurrent episodes of eating at night, such as eating after awakening from sleep or excess calorie intake after the evening meal. This eating behavior is not culturally acceptable by group norms, such as the occasional late-night munchies after a gathering. NES includes an awareness and recall of the eating, is not better explained by external influences such as changes in the individual's sleep-wake cycle, and causes significant distress and/or impairment of functioning. Though not defined specifically in "DSM-5", research criteria for this diagnosis proposed adding the following criteria (1) the consumption of at least 25% of daily caloric intake after the evening meal and/or (2) evening awakenings with ingestions at least twice per week.

Sufferers of ARFID have an inability to eat certain foods. "Safe" foods may be limited to certain food types and even specific brands. In some cases, afflicted individuals will exclude whole food groups, such as fruits or vegetables. Sometimes excluded foods can be refused based on color. Some may only like very hot or very cold foods, very crunchy or hard-to-chew foods, or very soft foods, or avoid sauces.

Most sufferers of ARFID will still maintain a healthy or normal body weight. There are no specific outward appearances associated with ARFID. Sufferers can experience physical gastrointestinal reactions to adverse foods such as retching, vomiting or gagging. Some studies have identified symptoms of social avoidance due to their eating habits. Most, however, would change their eating habits if they could.

Disordered eating describes a variety of abnormal eating behaviors that, by themselves, do not warrant diagnosis of an eating disorder.

Disordered eating includes behaviors that are common features of eating disorders, such as:

- Chronic restrained eating.

- Compulsive eating.

- Binge eating, with associated loss of control.

- Self-induced vomiting.

Disordered eating also includes behaviors that are not characteristic of any eating disorder, such as:

- Irregular, chaotic eating patterns.

- Ignoring physical feelings of hunger and satiety (fullness).

- Use of diet pills.

- Emotional eating.

- Night eating.

- "Secretive food concocting": the consumption of embarrassing food combinations, such as mashed potatoes mixed with sandwich cookies. See also Food craving § Pregnancy and Nocturnal sleep-related eating disorder § Symptoms and behaviors.

Shift work sleep disorder (SWSD) is a circadian rhythm sleep disorder characterized by insomnia and excessive sleepiness affecting people whose work hours overlap with the typical sleep period. There are numerous shift work schedules, and they may be permanent, intermittent, or rotating; consequently, the manifestations of SWSD are quite variable.

The primary symptoms of shift work sleep disorder are insomnia and excessive sleepiness associated with working (and sleeping) at non-standard times. Shift work sleep disorder is also associated with falling asleep at work. Total daily sleep time is usually shortened and sleep quality is less in those who work night shifts compared to those who work day shifts. Sleepiness is manifested as a desire to nap, unintended dozing, impaired mental acuity, irritability, reduced performance, and accident proneness. Shift work is often combined with extended hours of duty, so fatigue can be a compounding factor. The symptoms coincide with the duration of shift work and usually remit with the adoption of a conventional sleep-wake schedule. The boundary between a "normal response" to the rigors of shift work and a diagnosable disorder is not sharp.

Thorough history regarding frequency of bedwetting, any period of dryness in between, associated daytime symptoms, constipation, and encopresis should be sought.

The true primary hypersomnias include these: narcolepsy (with and without cataplexy); idiopathic hypersomnia; and recurrent hypersomnias (like Klein-Levin syndrome).

These eating disorders are specified as mental disorders in standard medical manuals, such as in the ICD-10, the DSM-5, or both.

- Anorexia nervosa (AN), characterized by lack of maintenance of a healthy body weight, an obsessive fear of gaining weight or refusal to do so, and an unrealistic perception, or non-recognition of the seriousness, of current low body weight. Anorexia can cause menstruation to stop, and often leads to bone loss, loss of skin integrity, etc. It greatly stresses the heart, increasing the risk of heart attacks and related heart problems. The risk of death is greatly increased in individuals with this disease. The most underlining factor researchers are starting to take notice of is that it may not just be a vanity, social, or media issue, but it could also be related to biological and or genetic components. The DSM-5 contains many changes that better represent patients with these conditions. The DSM-IV required amenorrhea (the absence of the menstrual cycle) to be present in order to diagnose a patient with anorexia. This is no longer a requirement in the DSM-5.

- Bulimia nervosa (BN), characterized by recurrent binge eating followed by compensatory behaviors such as purging (self-induced vomiting, eating to the point of vomiting, excessive use of laxatives/diuretics, or excessive exercise). Fasting and over-exercising may also be used as a method of purging following a binge.

- Muscle dysmorphia is characterized by appearance preoccupation that one's own body is too small, too skinny, insufficiently muscular, or insufficiently lean. Muscle dysmorphia affects mostly males.

- Binge Eating Disorder (BED), characterized by recurring binge eating at least once a week for over a period of 3 months while experiencing lack of control and guilt after overeating. The disorder can develop within individuals of a wide range of ages and socioeconomic classes.

- Other Specified Feeding or Eating Disorder (OSFED) is an eating or feeding disorder that does not meet full DSM-5 criteria for AN, BN, or BED. Examples of otherwise-specified eating disorders include individuals with atypical anorexia nervosa, who meet all criteria for AN except being underweight, despite substantial weight loss; atypical bulimia nervosa, who meet all criteria for BN except that bulimic behaviors are less frequent or have not been ongoing for long enough; purging disorder; and night eating syndrome.

Exercise bulimia is a subset of the psychological disorder called bulimia in which a person is compelled to exercise in an effort aimed at burning the calories of food energy and fat reserves to an excessive level that negatively affects their health. The damage normally occurs through not giving the body adequate rest for athletic recovery compared to their exercise levels, leading to increasing levels of disrepair. If the person eats a normally healthy and adequate diet but exercises in levels they know require higher levels of nutrition, this can also be seen as a form of anorexia.

Hypersomnia can be primary (of central/brain origin), or it can be secondary to any of numerous medical conditions. More than one type of hypersomnia can coexist in a single patient. Even in the presence of a known cause of hypersomnia, the contribution of this cause to the complaint of EDS needs to be assessed. When specific treatments of the known condition do not fully suppress EDS, additional causes of hypersomnia should be sought. For example, if a patient with sleep apnea is treated with CPAP (continuous positive airway pressure) which resolves their apneas but not their EDS, it is necessary to seek other causes for the EDS. Obstructive sleep apnea “occurs frequently in narcolepsy and may delay the diagnosis of narcolepsy by several years and interfere with its proper management.”

The most common sleep disorders include:

- Bruxism, involuntarily grinding or clenching of the teeth while sleeping.

- Catathrenia, nocturnal groaning during prolonged exhalation.

- Delayed sleep phase disorder (DSPD), inability to awaken and fall asleep at socially acceptable times but no problem with sleep maintenance, a disorder of circadian rhythms. Other such disorders are advanced sleep phase disorder (ASPD), non-24-hour sleep–wake disorder (non-24) in the sighted or in the blind, and irregular sleep wake rhythm, all much less common than DSPD, as well as the situational shift work sleep disorder.

- Hypopnea syndrome, abnormally shallow breathing or slow respiratory rate while sleeping.

- Idiopathic hypersomnia, a primary, neurologic cause of long-sleeping, sharing many similarities with narcolepsy.

- Insomnia disorder (primary insomnia), chronic difficulty in falling asleep and/or maintaining sleep when no other cause is found for these symptoms. Insomnia can also be comorbid with or secondary to other disorders.

- Kleine–Levin syndrome, a rare disorder characterized by persistent episodic hypersomnia and cognitive or mood changes.

- Narcolepsy, including excessive daytime sleepiness (EDS), often culminating in falling asleep spontaneously but unwillingly at inappropriate times. About 70% of those who have narcolepsy also have cataplexy, a sudden weakness in the motor muscles that can result in collapse to the floor while retaining full conscious awareness.

- Night terror, "Pavor nocturnus", sleep terror disorder, an abrupt awakening from sleep with behavior consistent with terror.

- Nocturia, a frequent need to get up and urinate at night. It differs from enuresis, or bed-wetting, in which the person does not arouse from sleep, but the bladder nevertheless empties.

- Parasomnias, disruptive sleep-related events involving inappropriate actions during sleep, for example sleep walking, night-terrors and catathrenia.

- Periodic limb movement disorder (PLMD), sudden involuntary movement of arms and/or legs during sleep, for example kicking the legs. Also known as nocturnal myoclonus. See also Hypnic jerk, which is not a disorder.

- Rapid eye movement sleep behavior disorder (RBD), acting out violent or dramatic dreams while in REM sleep, sometimes injuring bed partner or self (REM sleep disorder or RSD).

- Restless legs syndrome (RLS), an irresistible urge to move legs. RLS sufferers often also have PLMD.

- Shift work sleep disorder (SWSD), a situational circadian rhythm sleep disorder. (Jet lag was previously included as a situational circadian rhythm sleep disorder, but it doesn't appear in DSM-5 (see Diagnostic and Statistical Manual of Mental Disorders)).

- Sleep apnea, obstructive sleep apnea, obstruction of the airway during sleep, causing lack of sufficient deep sleep, often accompanied by snoring. Other forms of sleep apnea are less common. When air is blocked from entering into the lungs, the individual unconsciously gasps for air and sleep is disturbed. Stops of breathing of at least ten seconds, 30 times within seven hours of sleep, classifies as apnea. Other forms of sleep apnea include central sleep apnea and sleep-related hypoventilation.

- Sleep paralysis, characterized by temporary paralysis of the body shortly before or after sleep. Sleep paralysis may be accompanied by visual, auditory or tactile hallucinations. Not a disorder unless severe. Often seen as part of narcolepsy.

- Sleepwalking or "somnambulism", engaging in activities normally associated with wakefulness (such as eating or dressing), which may include walking, without the conscious knowledge of the subject.

- Somniphobia, one cause of sleep deprivation, a dread/ fear of falling asleep or going to bed. Signs of the illness include anxiety and panic attacks before and during attempts to sleep.

Other specified feeding or eating disorder or OSFED is the "DSM-5" category that replaces the category formerly called Eating Disorder Not Otherwise Specified (EDNOS) in "DSM-IV", and that captures feeding disorders and eating disorders of clinical severity that do not meet diagnostic criteria for anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), avoidant/restrictive food intake disorder (ARFID), pica, or rumination disorder. OSFED includes five examples: atypical AN, BN (of low frequency and/or limited duration), BED (of low frequency and/or limited duration), purging disorder, and night eating syndrome (NES).