Normally, people dream for more than two hours each night. Some of those dreams will be "bad dreams." These dreams may have disagreeable imagery or relate a story with a bad outcome—but they do not wake people from sleep, and the next morning, individuals feel little emotional residue.
Nightmares, on the other hand, can lead to emotionally disturbing feelings of fear, anxiety, or even terror. They can make a person experience sweating, an accelerated heart rate, or rapid breathing. If such a dream rouses a person from sleep, the individual may briefly shout or speak as they wake up. Nightmares can also lead to insomnia or other difficulties in the sleep cycle, and in some cases, even daytime distress.
A nightmare, if one occurs at all, usually takes place in the later hours of REM, or rapid eye movement, sleep. A dreamer often awakens with a solid general recollection of the imagery and content. Some researchers call these dreams “threat rehearsals,” during which we rehearse our responses to threats we may encounter in real life; other experts believe nightmares are one way that people work through stressful or upsetting events from their day.
For those experiencing the condition known as nightmare disorder, these disruptive nighttime experiences may occur as often as nightly, disrupting their daily lives and their mental health in a variety of ways.
Occasional bouts of nightmares do not require treatment. However, when nightmares become frequent to the point of causing dysfunction in someone’s work, school, and/or home life, the individual may be experiencing nightmare disorder (formerly called dream anxiety disorder) and should seek help.
The disorder’s symptoms, as cataloged by the DSM-5, include:
- Repeated occurrences of extended, extremely dysphoric, and well-remembered dreams that usually involve efforts to avoid threats to survival, security, or physical in­tegrity and that generally occur during the second half of the major sleep episode.
- On awakening from the dysphoric dreams, the individual rapidly becomes oriented and alert.
- The sleep disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.
- The nightmare symptoms are not attributable to the physiological effects of a substance (e.g., a drug of abuse or a prescription medication).
People with frequent nightmares or nightmare sleep disorder may develop insomnia, as they may try to avoid sleep out of fear of recurring nightmare experiences. These individuals may then experience excessive daytime sleepiness, poor concentration, depression, anxiety, or irritability.
Nightmare disorder is considered moderate if the disruptive dreams occur at least once a week, but not nightly and will be diagnosed as severe if episodes do occur nightly. Individuals with frequent nightmares or nightmare disorder are at substantially greater risk for suicidal ideation and suicide attempts, according to the DSM-5.
Nightmares may or may not have a connection to the events of a person’s daily life, but they more commonly do when the individual is experiencing post-traumatic stress disorder, of which “re-experiencing,” or flashbacks, is a common symptom. These involuntary recollections are often experienced as nightmares and they can be highly distressing. For those with PTSD and without, however, while nightmares may not fully replicate the details of a stressful experience, they may still have a strong indirect or symbolic link to such events.
They can. Generally, women report more nightmares revolving around sexual harassment, or the death or disappearance of loved ones, while men more often report having bad dreams involving physical aggression, war, or terror.
No. Nightmares and sleep terrors are identifiably different conditions. Nightmares tend to occur later in the sleep cycle, most often during REM sleep. People wake from them easily and completely and often can remember what was occurring in the dream. Sleep terrors, also called night terrors, involve repeated partial awakenings from deep sleep by intense fear, usually beginning with a cry or scream of panic; the individual may come out of bed but, like a sleepwalker, they will not be fully conscious. Unlike nightmares, night terrors typically happen in the first third of the night. The individual is confused, disoriented, and only partially responsive, if at all. The person generally does not recall either the experience or the content of the imagery that caused the terror.
People with a condition known as rapid eye movement (REM) sleep behavior disorder react physically to the situations they dream, vocalizing, screaming or engaging in sometimes violent motor behaviors while in the REM stage of sleep. This “dream enacting behavior” typically reflects the content of nightmares—often action-filled or violent dreams in which the person is being attacked or is trying to escape danger.
For more on symptoms, causes, and treatment, see Rapid Eye Movement Sleep Behavior Disorder.
Anxiety and stress are the primary causes of typical nightmares, and traumatic experiences can bring them on as well. According to the DSM-5, other causes of nightmares include major changes to one’s sleep schedule, sleep deprivation, jet lag, illness, and fever. Sleep apnea can in some cases cause nightmares, as can other sleep disorders such as narcolepsy or sleep terror disorder.
Nightmares can also occur as a side effect of certain prescription medications, drugs of abuse, tranquilizers, or sleeping pills; they can also be caused by drug withdrawal. Poor diet generally can be a cause of nightmares, as can eating, drinking alcohol, or consuming caffeine or other stimulants close to bedtime.
There are several medical conditions that are correlated with more frequent nightmares, as well as sleep problems more generally. Nightmares have been found to be comorbid, or to co-occur, with conditions including coronary heart disease, cancer, Parkinson’s disease, and chronic pain; they can also be a side effect of dialysis and of withdrawal from medications. In most cases, the stress surrounding the chronic illness is the likely reason that people experience more nightmares.
Nightmares are also frequently present with mental-health disorders including PTSD, insomnia, schizophrenia, psychosis, and mood, anxiety, adjustment, and personality disorders. Nightmares may also occur as one grieves during bereavement.
Nightmares generally are more frequent among children and adolescents, with decreasing rates of frequency as people age. As many as 4 percent of preschoolers may experience frequent nightmares, according to surveys of parents and the prevalence increases into adolescence for both boys and girls. After that, though, prevalence continues to rise in females; by age 29, nightmares may be twice as common among women as they are among men. Prevalence declines as people age, but remains higher in women. Overall, about half of all adults experience occasional nightmares, about 6 percent have a nightmare at least once a month, between 1 and 2 percent experience them more frequently, and less than 1 percent may experience the frequent nightmares that typify nightmare disorder, disrupt daily function, and lead them to try to avoid sleep.
To treat nightmares, one must address the underlying causes, and that usually means investigating one’s anxiety and stress levels. When nightmares occur that seem connected in content to the stress of one’s daily life, or when nightmares become more frequent after a traumatic event or life change, support from friends and relatives with whom one can openly share their feelings can help. If disruption persists, especially in the aftermath of trauma, consulting a mental health professional is recommended, as a therapist may be able to help an individual better cope with disturbing events or experiences.
Someone experiencing frequent nightmares or nightmare disorder may also benefit from exploring their physical health: Regular exercise and improved, consistent sleep hygiene may be very helpful. Physical activity often enables people to fall asleep faster and enjoy a deeper rest. Relaxation therapy to reduce muscle tension and lessen anxiety can also help.
As medication is frequently a source of disrupted sleep and nightmares, discussing prescription drugs with one’s physician may be necessary. Discontinuing medications, changing dosage, or trying alternatives may be beneficial.
If substance or alcohol abuse is present, that may very well be a primary underlying cause of the disorder, and if so, must be addressed through therapy or a support group.
Anyone experiencing nightmares more often than once a week, or whose nightmares prevent them from getting a good night’s rest, should contact their physician. The individual should be prepared with answers to these sleep hygiene and medical history questions:
• Is there a time pattern to the nightmares?
• Are the nightmares recurrent?
• Do they occur in the first or second half of the night?
• Do the dreams suddenly wake you from sleep?
• Do you feel intense fear or anxiety after the nightmare?
• Do you remember the imagery and the plot of the dreams?
• Have you recently been ill? If so, did you have a fever?
• Did you recently experience a stressful incident?
• What is your typical daily or weekly alcohol intake?
• Do you take medications?
• Do you use street drugs? If so, what do you use?
• Do you take natural supplements or alternative remedies?
• Are you suffer other symptoms besides disrupted sleep?
A physical exam may include neurological and psychological assessments, blood tests, an EEG, and tests for liver and thyroid function. If all of the above causes are ruled out, assessment by a sleep specialist who can administer a polysomnography, a test used to diagnose sleep disorders, may be necessary.
Psychotherapy approaches such as cognitive behavioral therapy or image reversal therapy can help reduce the frequency of nightmares for some patients by helping them manage their stress, anxiety, or response to trauma. Prescription medications used to treat conditions like PTSD, anxiety, or depression, such as olanzapine, clonidine, trazodone, and tricyclic antidepressants can sometimes be effective in reducing the occurrence of nightmares.
Frequent childhood nightmares (e.g., several per week) may cause significant distress to parents and children. Research confirms that parental soothing and reassurance can go a long way toward easing the lingering effects of a child’s disruptive dreams. However, nightmares are most likely to occur in children who have been exposed to stress or are experiencing anxiety, and so they may not resolve until those underlying stressors have been addressed.
Adhere to a routine and schedule every night and morning; going to sleep at the same time each night can help, as can avoiding sleeping in. Try to awake with the sun. Limit consumption of alcohol and caffeine and do not smoke. Exercise daily, relax before bedtime, and avoid lying in bed while awake. Keep your bedroom at a cooler temperature.
Sleep experts recommend that people who are prone to experiencing nightmares that appear to be tied to everyday stress work to focus on positive elements of the day that has ended, or of their lives in general, immediately before going to bed, and try to catch themselves when they find they are ruminating or catastrophizing, or dwelling on the content of recent disruptive dreams.
For those whose nightmares appear linked to PTSD, visualization treatments in which they replay traumatic memories in “safe” ways have shown the potential to deliver some relief.