Dreaming is one of the most complicated and mysterious aspects of sleep. While dreams can include visions of grandeur and bliss, they can also be scary, threatening, or stressful.
When a bad dream causes you to wake up, it’s known as a nightmare. It’s normal to occasionally have a nightmare or bad dream, but for some people, they recur frequently, disrupting sleep and negatively impacting their waking life as well.
Knowing the differences between bad dreams, nightmares, and nightmare disorder is a first step to addressing the causes of nightmares, starting appropriate treatment, and getting better sleep.
In sleep medicine, nightmares have a more strict definition than in everyday language. This definition helps distinguish nightmares from bad dreams: while both involve disturbing dream content, only a nightmare causes you to wake up from sleep.
Nightmares are vivid dreams that may be threatening, upsetting, bizarre, or otherwise bothersome. They occur more often during rapid eye movement (REM) sleep, the stage of sleep associated with intense dreaming. Nightmares arise more frequently in the second half of the night when more time is spent in REM sleep.
Upon waking up from a nightmare, it’s normal to be acutely aware of what happened in the dream, and many people find themselves feeling upset or anxious. Physical symptoms like heart rate changes or sweating may be detected after waking up as well.
While most people have nightmares from time to time, nightmare disorder occurs when a person has frequent nightmares that interfere with their sleep, mood, and/or daytime functioning. It is a sleep disorder known as a parasomnia. Parasomnias include numerous types of abnormal behaviors during sleep.
People who have occasional nightmares don’t have nightmare disorder. Instead, nightmare disorder involves recurring nightmares that bring about notable distress in their daily life.
It’s normal for both children and adults to have bad dreams and nightmares every now and again. For example, a study found that 47% of college students had at least one nightmare in the past two weeks.
Nightmare disorder, though, is far less common. Research studies estimate that about 2-8% of adults have problems with nightmares.
Frequent nightmares are more common in children than in adults. Nightmares in children are most prevalent between the ages of three and six and tend to occur less often as children get older. In some cases, though, nightmares persist into adolescence and adulthood.
Nightmares affect males and females, although women are generally more likely to report having nightmares, especially during adolescence through middle age.
There is no consensus explanation for why we have nightmares. In fact, there is an ongoing debate in sleep medicine and neuroscience about why we dream at all. Many experts believe that dreaming is part of the mind’s methods for processing emotion and consolidating memory. Bad dreams, then, may be a component of the emotional response to fear and trauma, but more research is needed to definitively explain why nightmares occur.
Sleep terrors, sometimes called night terrors, are another type of parasomnia in which a sleeper appears agitated and frightened during sleep. Nightmares and sleep terrors have several distinguishing characteristics:
Many different factors can contribute to a higher risk of nightmares:
Though not fully understood, a genetic predisposition may exist that makes it more likely for frequent nightmares to run in a family. This association may be driven by genetic risk factors for mental health conditions that are tied to nightmares.
Some evidence indicates that people who have nightmares may have altered sleep architecture, meaning that they progress abnormally through sleep stages. Some studies have also found a correlation between nightmares and obstructive sleep apnea (OSA), a breathing disorder that causes fragmented sleep, although further research is needed to clarify this association.
Nightmares can have a clear connection to things that happen while you’re awake. Nightmares tied to anxiety and stress, especially PTSD, may involve flashbacks or imagery that is directly linked to traumatic events.
However, not all nightmares have an easily identified relationship to waking activity. Nightmares can have bizarre or bewildering content that is difficult to trace to any specific circumstances in a person’s life.
Nightmares, especially recurrent nightmares, can have a significant impact on a person’s sleep. People with nightmare disorder are more likely to suffer from decreases in both sleep quantity and quality.
Sleep problems can be induced by nightmares in several ways. People who have nighttime disruptions from nightmares may wake up feeling anxious, making it hard to relax their mind and get back to sleep. Fear of nightmares may cause sleep avoidance and less time allocated to sleep.
Unfortunately, these steps can make nightmares worse. Sleep avoidance can cause sleep deprivation, which can provoke a REM sleep rebound with even more intense dreams and nightmares. This often leads to further sleep avoidance, giving rise to a pattern of disturbed sleep that culminates in insomnia.
Nightmares may exacerbate mental health conditions that can worsen sleep, and insufficient sleep can give rise to more pronounced symptoms of conditions like depression and anxiety.
Insufficient sleep connected to nightmares and nightmare disorder can cause excessive daytime sleepiness, mood changes, and worsened cognitive function, all of which can have a substantial negative impact on a person’s daytime activities and quality of life.
Because it’s common to have an occasional nightmare, some people may find it hard to know when nightmares are a cause for concern. You should talk to your doctor about nightmares if:
To help your doctor understand how nightmares are affecting you, you can keep a sleep diary that tracks your total sleep and sleep disruptions, including nightmares.
Infrequent nightmares don’t normally need any treatment, but both psychotherapy and medications can help people who have nightmare disorder. By reducing nightmares, treatments can promote better sleep and overall health.
Treatment for nightmares should always be overseen by a health professional who can identify the most appropriate therapy based on a patient’s overall health and the underlying cause of their nightmares.
Psychotherapy, also known as talk therapy, is a category of treatment that works to understand and reorient negative thinking. Talk therapy has broad applications in addressing mental health disorders and sleeping problems like insomnia.
Many types of psychotherapy fall under the umbrella of cognitive-behavioral therapy (CBT), including a specialized form of CBT for insomnia (CBT-I) that may be used to treat nightmares. A central component of CBT is reorienting negative thoughts and feelings and modifying detrimental patterns of behavior.
There are numerous types of talk therapy and CBT that may help reduce nightmares:
Behavioral recommendations associated with talk therapy frequently involve changes to sleep hygiene. This includes making the bedroom more conducive to sleep as well as cultivating daily routines and habits that facilitate consistent sleep.
Many psychotherapies for nightmares involve a combination of methods. Examples include CBT-I, Sleep Dynamic Therapy and Exposure, Relaxation, and Rescripting Therapy (ERRT). Mental health professionals can tailor talk therapy for nightmares to fit a patient, including, when appropriate, account for a coexisting mental health disorder.
Several types of prescription medications may be used to treat nightmare disorder. Most often, these are medications that affect the nervous system such as anti-anxiety, antidepressant, or antipsychotic drugs. Different medications may be used for people who have nightmares associated with PTSD.
Medications benefit some patients, but they can also come with side effects. For that reason, it is important to talk with a doctor who can describe the potential benefits and downsides of prescription drugs for nightmare disorder.
If you have nightmares that interfere with your sleep or daily life, the first step is to talk with your doctor. Identifying and addressing an underlying cause can help make nightmares less frequent and less bothersome.
Whether nightmares are common or occasional, you may get relief from improving sleep hygiene. Building better sleep habits is a component of many therapies for nightmare disorder and can pave the way for high-quality sleep on a regular basis.
There are many elements of sleep hygiene, but some of the most important ones, especially in the context of nightmares, include: