Common Nightmares That May Actually Be Warnings

What Is a Nightmare?

Nightmares are elaborate, vivid, dysphoric story-like sequences of dream mentation that are usually accompanied by negative emotions, like fear or anxiety and are remembered upon awakening. They usually occur during the second half of the night when longer periods of rapid eye movement (REM) sleep occur.

A bad dream is a less intense version of a nightmare that does not result in abrupt arousal from sleep. Nightmares can also be differentiated from night terrors, which are arousals from slow-wave sleep (NREM stages 3 and 4) with no recollection of dream content and, in most cases, amnesia for the awakening itself.

Why Do Nightmares Occur?

A common thread through many theories of why nightmares occur involves working through memories and emotions to consolidate and modulate our perception of ourselves and our environment. During REM sleep, brain areas involved in memory and emotion (e.g., hippocampus and amygdala) generate dream elements that prefrontal areas (e.g., medial prefrontal and anterior cingulate cortex) try to organize, temper, and reframe.

The sleeping brain in REM is able to consider distressing thoughts and emotions without the autonomic nervous system reacting (e.g., increased heart rate, heavy breathing, etc.); this desomatization is believed to help us adapt to our environment in waking life. However, when the dream elements are excessively distressing, the mechanisms that normally temper the autonomic response fail. The result is a sudden autonomic arousal from sleep with a memory of the nightmare just experienced.¹

Are Nightmares and Nightmare Disorder the Same Thing?

Bad dreams and nightmares that occur sporadically can be adaptive and healthy. However, if nightmares become frequent and interfere with daily life, a person may be diagnosed with nightmare disorder. Nightmare disorder is considered acute if it has been happening for less than one month, subacute if between one and six months, and persistent if more than six months.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for nightmare disorder is as follows:

• Nightmares occur repeatedly (severity can be mild: less than 1 episode per week; moderate: one or more episodes per week; or severe: nightly episodes)
• Nightmares usually occur during the second half of major sleep episodes
• Individual recalls dream details vividly
• Upon awakening from the nightmare, the individual is oriented and alert (in contrast to waking up from a night terror)
• Distress from the nightmare interferes with  social, occupational, and other areas of daily functioning
• Nightmares are not attributable to substance use (e.g., medication, recreational drug, substance misuse, or substance withdrawal)
• Nightmares are not explained by coexisting mental and medical disorders

Types of Nightmares

When a nightmare is linked to a trauma that occurred during waking life, it is termed a post-traumatic nightmare. Nightmares for which the cause is unknown are called idiopathic nightmares and are generally less intense and frightening. Anecdotally, nightmares have been described as recurring, vivid, fever-induced, and stress-induced, but these are not official diagnostic terms used by the DSM-5.

Most Common Nightmares Themes

While nightmare details may be specific to the individual, there are some general themes that tend to occur more than others. Robert & Zadra examined nightmares and found physical aggression to be the most common nightmare theme and interpersonal conflict to be the most common bad dream theme.²

It is also possible to have multiple themes intertwined in a dream.

Common nightmare themes may include:

• Physical aggression: Acts of threat or attack of one’s physical body, such as sexual aggression, murder, being punched and being abducted; comprises 48% of nightmare reports and 21% of bad dreams.3
• Interpersonal conflict: Hostility, opposition, insult, humiliation, rejection, infidelity, and lying; comprises 21% of nightmares and 35% of bad dreams.⁴
• Failure or helplessness: Being late, lost, unable to talk, losing, forgetting something important, or erring; comprises 16% of nightmares and 18% of bad dreams.⁵
• Misfortune: Losing one’s job, house, money, or other valuable; comprises 72% of nightmares and 67% of bad dreams. By comparison, misfortune is a theme that arises in 43% of everyday dreams but does not lead to the intense emotion of a nightmare or bad dream.⁶
• Being chased: Being pursued by another person, animal, or creature, but without being attacked, comprises 11-26% of nightmares and 6% of bad dreams.^7,8
• Health-related concerns and death: Disease, medical diagnoses or treatments, physical illness, tooth or hair loss, or death of oneself or another character in the dream; comprises 9% of nightmares and 14% of bad dreams.⁹ Other studies found death and murder to constitute 15-64% of nightmares, with the death of family or friends occurring more frequently than one’s death.^10,11,12
• Suffocation: Restricted from breathing from suffocation or choking; this theme may be more common for individuals with sleep apnea, and one study reported this theme’s occurrence at 30%.¹³
• Evil force: Sensing the presence or being possessed by an evil entity such as a monster, alien, ghost, or demon; comprises 11% of nightmares and 5% of bad dreams.¹⁴
• Accident: Being the victim of or cause of an accident such as a car crash, drowning, slip and fall; comprises 9% of nightmares and 5% of bad dreams.¹⁵
• Disaster and calamity: Being involved in a fire, flood, earthquake, war, or apocalypse; comprises 6% of both nightmares and bad dreams.¹⁶
• Insects and vermin: Infestation, bites or stings of insects (e.g., spiders), snakes, rodents, or other creatures; comprises 7% of nightmares and 4% of bad dreams.¹⁷
• Environmental abnormality: Bizarre or nonsensical events such as riding a roller coaster off the tracks and into the sky, oversized creatures, or being at a funeral dressed in a wedding gown; comprises 5% of nightmares and 4% of bad dreams.¹⁸
• Paralysis: Inability to move despite trying to; one study found paralysis to be the featured theme in 25% of dream reports.¹⁹ Paralysis is a common theme for sleep paralysis episodes, a sleep phenomenon in which the brain awakens but is still infused with REM dream mentation and atonia (muscle inhibition normal to REM sleep).

Most Common Nightmare Emotions

In addition to examining nightmare themes, studies have also distinguished common emotions that are felt during or after a nightmare. Not surprisingly, fear is the most common emotion to arise in nightmares (65% of nightmare reports), but other experienced emotions include sadness (7%), anger (5%), confusion (3%), disgust (3%), frustration (3%), guilt (2%) and even some unexpected positive emotions (5%).²⁰

15 Possible Warnings Your Nightmares May Be Indicating

An estimated 85% of people experience a nightmare at least once a year, but only 2% of the general population experience nightmares weekly.^8,9,10 When nightmares occur frequently, they may be an indicator of a physical or mental health concern that may benefit from attention. Indeed, nightmares occur more frequently with certain mental disorders and medical conditions.

Here are fifteen possible warnings your nightmares may be indicating:

1. Past Trauma

Trauma can be a key ingredient for nightmare activity. In fact, 67%-75% of individuals with post-traumatic stress disorder (PTSD) also experience nightmare disorder. For these individuals, nightmares tend to resemble real past events and be repetitive (i.e., recurring nightmares).⁹ Trauma, such as childhood trauma or sexual trauma, can underlie nightmares and other mental health symptoms for years and even decades later.¹¹

2. Vulnerability to Future Trauma

In addition to trauma contributing to nightmares, studies have also found that people who tend to have frequent nightmares are more vulnerable to trauma in the future.¹² Factors like genetics and personality characteristics may increase this vulnerability. For example, people with “thin boundaries” tend to be more emotionally sensitive, reactive to external and internal (e.g., bodily sensations) influences, and have more nightmares than those with “thick boundaries.”¹³

3. Too Many Stressors

Dreams, good and bad, have a role in processing emotions, thoughts, and experiences you have during the day. When daily stressors pile too high, your brain’s mechanism for digesting all these elements becomes overloaded, and nightmares may ensue. If you are experiencing nightmares, consider exploring with a mental health professional what life stressors and perhaps upcoming transitions may be contributing.

4. Schizophrenia Spectrum Disorder

It is not clear whether individuals with schizophrenia experience more nightmares than individuals who do not have this mental health disorder, as the research is mixed. One study suggests that nightmares can occur more during the prodromal (i.e., initial) period before the onset of psychotic symptoms.¹⁴

5. Depressive Disorders

One study on nightmares found that individuals who experienced frequent nightmares had a higher risk of suicide than individuals with occasional nightmares.¹⁵ While it is possible that trauma may underlie both nightmares and suicidality, frequent nightmares may be an indication of unconscious or subconscious trauma for which therapeutic intervention may be effective.

6. Bipolar Disorder

Individuals with bipolar disorder can experience both depressive and manic symptoms. While nightmares do occur more frequently with bipolar disorder, it is not as common as with depression.¹⁶

7. Anxiety Disorders

Given that overactive amygdala activity is associated with both anxiety disorders and nightmares, it is not surprising that an estimated 16% of individuals with anxiety disorder also experience nightmare disorder.^17,18 Studies have shown an increase in nightmare frequency for generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD) and panic disorder.^19,20,21

8. Eating Disorders

Individuals with anorexia nervosa or bulimia nervosa tend to have more negative dream content and emotionality than people who do not have these medical conditions.⁹ Youth experiencing a comorbidity of nightmare disorder and eating disorder also have an elevated risk of suidality.²²

9. ADHD

Certain subtypes of attention-deficit/hyperactivity disorder (ADHD) (i.e., combined ADHD, hyperactive-impulsive ADHD) are associated with REM sleep overdrive or a tendency towards longer and earlier REM periods in adults and children.²³ These lengthier REM periods may underlie the increased risk of nightmares in people with ADHD.

10. Personality Disorder

Nightmare disorder has a prevalence of 31% in people with a personality disorder. In particular, borderline personality disorder (BPD) is associated with a relatively high frequency of nightmares. Individuals with comorbid BPD and nightmare disorder have a greater risk for substance misuse and suicidality than those without nightmare disorder.²⁴

11. Asthma

Nightmares occur more frequently in people with asthma, especially children (10%).²⁵ Night terrors in young children with severe asthma are even more frequent (50%).²⁶Nightmares may result from the dream narrative reflecting a physiological airway obstruction like suffocation or as a side effect of certain asthma medications. It has also been suggested that nightmares can provoke an asthmatic attack.²⁷

12. Migraine

There is a connection between migraines and nightmares, albeit not well understood. Emotional suppression during wakefulness, and in particular suppression of anger and anxiety, seems related to unpleasant dreams, often with smell and taste dream elements.^28,29,30 Resolving issues giving rise to negative emotions before sleep can potentially reduce nightmare occurrence.⁸

13. Substance Misuse

Several substances can increase the likelihood of a nightmare, such as antidepressants, stimulants (e.g., amphetamine, cocaine), smoking cessation aids, melatonin, medications that affect dopamine levels, and blood pressure medication.⁹ Withdrawal from substances that normally suppress REM sleep (e.g., alcohol withdrawal) can lead to REM rebound and increased risk of nightmares.

14. Too Much REM Sleep

Approximately 33% of people with narcolepsy experience nightmares, which is about six times higher than the general population.³¹ Narcolepsy is associated with sudden loss of muscle tone, excessive sleepiness, and abnormally early and irregular REM sleep activity.

Excess REM sleep activity likely gives rise to a landscape conducive to nightmares. Other conditions that are accompanied by REM sleep overdrive – when a person has longer and earlier than normal REM periods – include schizophrenia, depression, anxiety, OCD, PTSD and mood disorders.³²

15. Insomnia

Insomnia is another sleep disorder that often goes hand in hand with nightmare disorder, with nightmares reported by 18% of people with insomnia.³³ Frequent nightmares can lead to anxiety about falling asleep. Wouldn’t you want to avoid something unpleasant and distressing?

Unfortunately, insomnia is particularly comorbid with post-traumatic nightmares, mood and anxiety disorders, particularly in women. Leaving these conditions untreated can exacerbate symptoms as the resulting sleep-deprived brain will become increasingly less able to process anxiety, mood, and cognitive deregulation. There are treatments that can help stop the ensuing vicious cycle.

How to Improve Your Sleep

Routine healthy sleep is crucial to daily functioning; however, too little or too much sleep can easily spin into poor sleep habits and sleep architecture and a greater risk for mental health symptoms. Nightmares can result from too much sleep and extended time in REM sleep. Consistently getting the right amount of sleep can be achieved with good sleep hygiene.

Here are some tips on how to improve your sleep:

• Install blackout shades
• Minimize screen time starting 1 hour before going to bed
• Avoid caffeine and other stimulants after 2 pm
• Avoid eating close to bedtime
• Avoid alcohol before bed
• Avoid napping for more than 20 minutes during the day
• Keep the ambient temperature on the cooler side
• Keep a consistent, reasonable bedtime each night
• Create a bedtime routine for the hour before you intend to sleep
• Do not do work or other stimulating activities in bed
• Do engage in relaxing activities like mild stretching, yoga, and meditation
• Discuss sleep changes and irregularities with your healthcare provider
• Make an appointment with or request a referral to a sleep specialist for evaluation

Treatment for Underlying Causes of Nightmares

While stress and anxiety can contribute to the occurrence of nightmares, they can also result from the nightmare experience, leading to a vicious cycle of anxiety, sleep disorder (e.g., insomnia), and related symptoms like fatigue, mood changes, and substance misuse. Discussing your experience of frequent nightmares with a healthcare professional is the first step to identifying and treating underlying conditions.

Depending on the underlying cause of the nightmares, treatment may involve:

• Cognitive behavioral therapy (CBT): When nightmares are accompanied by difficulty falling asleep at night or waking up in the middle of the night and not falling back asleep, CBT-i is specifically targeted to treat insomnia.
• Psychotherapy: Within the context of modern psychotherapy, the psychotherapy approaches (and their offshoots) spawned by Sigmund Freud were the first to analyze dreams, including nightmares.  Though dream symbol dictionaries and stereotyped interpretations are popular, they’re largely unreliable. A skilled practitioner can help an individual determine why elements appear in dreams that are otherwise blocked by one’s defense mechanisms during waking hours.
• Learning to cope with triggers (LCT): LCT is a behavioral approach that is effective for treating chronic headaches and migraines. When nightmares are comorbid with migraines, LCT can be helpful.³⁴
• Eye movement desensitization and reprocessing (EMDR): EMDR is a behavioral approach that involves recalling dream content to reprocess together with therapist-guided eye movement spurts lasting 24 seconds.³⁵ Combining eye movement behavior with the gradually less distressing content is believed to create a new, less distressing association so that when in rapid-eye-movement (REM) sleep, the mentation won’t be so scary and less likely to result in arousal.
• Hypnotherapy: Hypnotherapy works by putting the individual into a trance-like state, the therapist can guide the person to reprocess nightmare content to be less fearful. By suggesting changes to the dream narrative, one study found hypnosis effective for 71% of participants experiencing nightmares.³⁶
• Progressive muscle relaxation (PMR): PMR involves the sequential tensing and releasing of muscles, like in a body scan meditation. The physical relaxation of body parts is believed to translate to less stress and anxiety to feed subsequent nightmare mentation.³⁷ This method can also help with insomnia, which often accompanies nightmare disorder.
• Imagery rehearsal therapy (IRT): IRT is a behavioral therapy in which you recall and reframe the nightmare details to less distressing content and rehearse the new script. Based on the idea that dreams serve to process and integrate newly learned material with existing concepts, IRT has been shown to be particularly effective for nightmares.³⁸
• Lucid dreaming therapy: Similar to IRT, lucid dreaming is a trainable skill where the sleeping individual becomes aware that they are dreaming and can alter the course of the dream.³⁹ Often combined with rehearsal of an alternate narrative during wakefulness, this method can be effective if the person is, in fact, able to lucid dream – not everyone can.
• Medication: While medication can be used to treat nightmare disorder (e.g., atypical antipsychotics, benzodiazepines, tricyclic antidepressants), depending on the underlying cause and if PTSD is present, some of these pharmaceuticals can actually increase nightmares. Your physician may want to adjust your medication regimen (e.g., type, dosage, timing) to reduce your risk of nightmare mentation.
• Substance misuse treatment: Since some misused substances like amphetamine and cocaine can lead to nightmares, removing the offending substance can help reduce nightmares. In the case of addiction, medical assistance and related support will likely be needed to withdraw and stay in remission. Withdrawal itself, especially from alcohol, can also increase nightmare mentation.

When to Seek Professional Help

If you or someone you care about is experiencing frequent nightmares, it may indicate an underlying condition that can benefit from attention. A good first step is to discuss with your doctor, sleep specialist, or therapist options for evaluation and treatment. If you need help finding a therapist or psychiatrist for in-person or virtual treatment, you can ask a trusted friend or physician or search an online therapist directory.

In My Experience

Dreaming serves an important role in how we process our inner thoughts and feelings and our relationship to our environment. Good or bad, dreaming is adaptive, built-in to our biology. Most of us will experience a nightmare at least once a year, and that is perfectly normal. When nightmares occur more frequently and start to disturb your ability to fall asleep at night or function during the day, it is a problem for which there are treatments.