How Do Dreams Affect Sleep Quality? | Sleep Foundation

At the same time, though, nightmares can disrupt sleep and even affect a person during their waking hours.

Given that virtually everyone has dreams, both good and bad, it’s natural to wonder how dreaming affects sleep quality, whether nightmares are bad for sleep, and how to avoid bad dreams.

Dreaming is a normal part of healthy sleep. Good sleep has been connected to better cognitive function and emotional health, and studies have also linked dreams to effective thinking, memory, and emotional processing. In this way, many experts believe dreaming is either a reflection of or a contributor to quality sleep.

However, not all dreams are created equal. Some dreams may have a negative impact on sleep. Bad dreams involve content that is scary, threatening, or traumatic. When a bad dream causes an awakening from sleep, it can be considered a nightmare⁶ .

Most people have a bad dream or nightmare every once in a while with no notable impact on their sleep quality. When nightmares happen often, though, they can become a barrier to sleep. For some people, nightmares occur multiple times per week and/or more than once in any given night.

Nightmare disorder can be loosely defined as the occurrence of frequent nightmares that interfere with a person’s sleep and/or their mood or thinking during the day⁷ . People with nightmare disorder may have restless sleep with more awakenings and greater difficulty getting back to sleep. In addition, they may avoid sleep because of their fear of disturbing dreams, increasing their risk of insomnia and sleep deprivation.

People should talk with their doctor8  if they have nightmares more than once a week, have their sleep disrupted by nightmares, or notice that their daytime mood, thinking, or energy level is affected by nightmares. A doctor can work with them to identify the most likely cause and optimal treatment to reduce these bothersome dreams.

Dreaming is a normal part of healthy sleep. Good sleep has been connected to better cognitive function and emotional health, and studies have also linked dreams to effective thinking, memory, and emotional processing. In this way, many experts believe dreaming is either a reflection of or a contributor to quality sleep.

However, not all dreams are created equal. Some dreams may have a negative impact on sleep. Bad dreams involve content that is scary, threatening, or traumatic. When a bad dream causes an awakening from sleep, it can be considered a nightmare⁶ .

• Healthy dreaming may be indicative of quality sleep that facilitates sharper thinking, better mood, and overall health.
• Dreaming may provide for more expansive or inspirational thinking, forming the underlying concept behind the maxim to “follow your dreams.”
• Dreaming may enhance memory consolidation, making it easier to remember important information.

• People with mental health disorders, such as anxiety or post-traumatic stress disorder (PTSD), may experience worse symptoms as a result of recurring nightmares.
• Nightmares may interrupt sleep, causing daytime sleepiness, worsened mood, or thinking problems during the day.

If you have frequent bad dreams, start by talking with your doctor who can help determine if you have nightmare disorder. Treatment for nightmare disorder can include behavioral therapy and/or medications.

Improving habits and sleep hygiene can help reduce bad dreams. Some specific tips include:

• Practice relaxation techniques to minimize stress and anxiety, both of which can provoke nightmares.
• Give yourself time to wind down before bed in a calm and comforting bedroom environment.
• Avoid screen time for an hour or more before bed, and make sure not to watch scary or bothersome content at night.
• Don’t drink alcohol, which affects your REM sleep, in the evening and especially before bed.
• Keep a consistent sleep schedule, even on weekends, to avoid sleep deprivation, which can spur more REM sleep and intense dreaming.

Many factors influence dreaming, but it is not clearly established that sleeping position is one of those factors.

Some researchers have theorized that dream content may vary based on a person’s sleeping position because physical sensations and pressure applied to the body are different for back, stomach, and side sleepers. One study found that people who sleep on their left side were more likely to have nightmares¹¹ , and another found that vivid dreams, including some nightmares and erotic dreams, were more common in stomach sleepers¹² .

A limitation of these studies, though, is that they relied on self-reported data, which is subject to inaccuracies. For example, many people switch their sleeping position during the night without being aware of it. In addition, prior research has shown that sleep position doesn’t affect the amount of time spent in the different sleep stages13 .

Overall, more robust research is needed to establish a link between sleeping position and nightmares.