Then, you wake up in a cold sweat—your heart rate is still elevated from your dream anxiety before it ebbs away as you realize that you’ve been out of college for ten years now. It was just a bad dream.
But why does this happen and why does it feel so real?
Despite years of research and lab tests, science still doesn’t have an actual answer for what causes dreams—but there are several promising hypotheses pointing to potential explanations. What are dreams made of? Images, sounds, and feelings jumbled up in ways that sometimes suggest underlying meanings, a kind of byproduct from your brain sorting out the “noise” of your thoughts.
This is our guide to dreams, their significance, and how they relate to the rest of your waking life.
What are dreams?
At the onset of sleep, a few biological changes happen: your heart rate slows, a regular breathing pattern takes over, and your body temperature cools off. This first sleep stage is when your brain starts to pick through the thoughts, images, and emotions that filled your day. It’s unlikely you’ll remember any dreams in the pre-REM dream stage unless you happen to wake up during them.
After around 90 minutes of being asleep, sleepers transition into the rapid eye movement (REM) stage. As you enter this stage, your heart rate and respiration quicken. This is when you’ll experience vivid, surreal dreams where you might fly, fall, and otherwise sort out your subconscious thoughts in a dream environment. During the REM stage, the amygdala, your brain’s emotion processor, and the hippocampus, your brain’s memory center, are actively providing the powerful, emotional content of our dreams. Meanwhile, your frontal and prefrontal cortices, where your brain uses logic to process information, are suppressed.
Think of dreams this way: during the day when you’re awake, your brain takes in information from external stimuli. During a dream, your brain is making sense of internal stimuli.
Scientists believe that the images you see in your dreams stem from your stored memories. This is because your visual processing center, which takes in information while you’re awake, is inactive during sleep. The portion of your brain that houses your visual memory stores, on the other hand, is highly active. So, that’s why you might have a bizarre dream that takes place in your first-grade classroom, for example.
While your brain goes into overdrive during your dream, your voluntary muscles stay paralyzed. This is your body’s way of ensuring you won’t act out your dreams and try fighting that monster in real life. Luckily, your involuntary muscles keep doing their thing while you’re dreaming. For example, your heart continues to beat without you thinking about it, but may beat faster if you’re experiencing an anxiety-inducing or exciting dream.
If you get between 6 and 8 hours of sleep, you’ll cycle through around 4 to 6 REM sleep stages during which you’ll dream. Each time you go through this sleep stage, the REM period gets longer, starting out at just ten minutes while the last REM cycle may last up to an hour. This is one of the many reasons why it’s important to prioritize the amount of sleep you get each night. REM sleep is when the areas of your brain responsible for memory recollection and learning are active—in fact, that’s one function many scientists believe dreams serve. We’ll get into that below.
Why do we have dreams?
The purpose of our dreams hasn’t been proven by science in concrete terms. But sleep scientists have some theories about dreams that we’ll dig into.
According to leading sleep psychologists, one major function of dreaming is that they allow our brains to process complex or difficult emotions. For many, dreams can help cope with loss and trauma. For those that have lost loved ones, for example, dreams may be an important emotional coping mechanism that helps the dreamer grieve. Right after the death of a loved one, dreams tend to revolve around the loved one suddenly reappearing but as time goes on, dreams about lost family and friends may become more reassuring. This may mirror the real-life grieving process, as those grieving can slowly accept the loss, rather than dwelling on the initial shock and disbelief phases of grief.
Dreaming may also help lower emotional reactivity which was demonstrated in a study on veterans who suffer from PTSD.
Comprehending new experiences
REM dreams help connect old events to new events to give you more context. Part of your brain’s job when you sleep is to sort through old memories and compare them to new ones to see if they’re relevant. For example, if you’re anxious about fitting in at a new job or doing well at a job interview, you may have a dream from a period in your life where you felt anxious like your first day at a new school. By processing this emotion in your dream, you may be better prepared to appropriately deal with that emotion in your waking life.
Memory consolidation and learning
One popular theory about why we dream is that they help your brain divide up what memories are important to store away and which can be forgotten. For example, if you learn new information and go to sleep, the next day you’ll have better recall than if you hadn’t slept, according to research by the American Physiological Society.
In a study that required participants to solve a visual maze, half of the participants watched a video after seeing a maze and the other half took a 90-minute nap. Those who took a nap and dreamt about the maze were significantly better at completing the maze. This suggests that dreaming enhances your ability to creatively solve a problem because of your brain’s ability to place new information within the context of pre-existing knowledge during a dream.
It’s most likely that dreaming serves a variety of purposes that don’t fall under one specific category. But what is clear is that dreaming is an essential part of how we form long-term memories, as well as how your brain decides what’s important to hold onto and what gets eliminated.
What are nightmares?
While dreams may often just be a weird collage of ideas, emotions, places, and people you’ve seen, they can also be intense, terrifying, and may suddenly cause you to wake up. Nightmares tend to be realistic but disturbing dreams that jolt you awake from fear. They will typically occur during the REM stage of your sleep cycle when most dreams occur. They may stem from real-life stress, an anxiety disorder, PTSD, drug addiction, or sleep apnea.
Around 85% of adults report having at least one nightmare last year but only 4 to 10% of people report having frequent nightmares. If nightmares are frequent where you feel anxious about going to sleep, or they’re constantly interrupting your sleep and causing a decline in your sleep quality, it’s a good idea to consult a physician who may be able to help.
Related to nightmares are night terrors where the sleeper may shout, yell, flail, or sleepwalk during non-REM sleep. Adults can experience night terrors, but they are more common in young children, especially between the ages of 3-12. Psychologists believe that because children are smaller, their night terrors are a kind of subconscious manifestation of their physical vulnerability. Children also have fewer coping mechanisms to deal with intense emotions and night terrors might be one of the side effects.
Sleep paralysis is another highly intense type of nightmare or night terror where your mind is conscious but you can’t move your body during REM sleep. These intense experiences are sometimes due to your mind regaining consciousness before your REM cycle is done. It can cause unsettling hallucinations and can make you hyperventilate.
While you can’t totally prevent sleep paralysis, you can take steps to reduce the likelihood of experiencing it by avoiding sleeping on your back and establishing a consistent sleep schedule.
Recurring dreams such as dreams of being chased or falling are dreams that keep cropping up during the dream state. These types of dreams lean toward more negative than regular dreams and are linked to real-life psychological stress in both children and adults. Psychiatrists also theorize that they’re a manifestation of unmet psychological needs. However, it’s hard to pinpoint the exact reason for recurring dreams, and your best bet is often to simply take steps to improve your overall emotional wellness during your waking life.
There are dream themes that are common across the world regardless of gender, culture, or age. According to one survey, the four most commons types of dreams are the following:
- Sexual experiences
- Being chased
What’s lucid dreaming?
Lucid dreaming is characterized by higher-than-usual brain wave activity in the prefrontal cortex, the area of your brain that deals with higher-level information processing, logic, and language. Typically, they are a much more vivid dream experience where the dreamer is aware he or she is dreaming and has some element of control over what happens in the dream. There are ways to practice lucid dreaming, and it’s a low-risk way to create a kind of “mental rehearsal space” where you can practice different real-life scenarios.
How can I encourage good dreams?
Your waking life has a huge impact on your sleep and sleep quality—and vice versa. One of the best ways to ensure you’re whisked off to sleep is by practicing good sleep hygiene and creating a positive sleep environment where your sleep is less likely to be disrupted. For example, if you tend to get hot while sleeping, a cooling copper mattress may be the answer. Sleeping in a cooler room or using a cooling copper mattress topper can help your body naturally transition into sleep faster. You’ll also want to avoid using blue-light emitting devices, consuming alcohol or caffeine near bedtime, and establishing a sleep schedule.
What are dreams made of?
The Layla mattress is what dreams are made of—at least when it comes to your dream bedroom. While scientists may never truly nail down the reason for dreams, studies suggest that they’re an important aspect of healthy sleep. So, set up your dream bedroom, relax into a comfortable mattress, and start dreaming.