Throughout the history of recorded civilization, people have tried to understand the origin and purpose of dreams, yet these experiences are still one of the greatest mysteries of life. For example, do recurring ones have important messages to convey? Are we capable of sleep-induced prophetic visions? And a popular favorite: What does it mean when teeth fall out in a dream? (We’ll share a few theories in a moment).
Explanations for types of dreams vary but surprisingly, researchers never tire of exploring the possibilities. While oneirology — the scientific study of dreams — usually focuses more on brain function, clinical dream analysis is one of the many methods used to define meaning.
Are you wondering why you had a particular dream last night? Let’s see what theories help explain it.
Why Do We Dream?
Psychiatry pioneers Sigmund Freud and Carl Jung are probably most well known for dream interpretation and analysis, but modern-day scientists have also made significant advances within the past century that align more with scientific discovery.
Dr. Zlatan Križan is a professor of psychology at Iowa State University (ISU). He says there are numerous theories about why we dream.
“While most people focus on the conscious content of dreams — the stories we regale ourselves with in the morning — dreaming involves changes to how the whole brain does its business,” he says. “One way to think about dreaming is a process of sorting and filing through all the important information we experienced during the day.”
Rosalind Cartwright founded Rush University Medical Center’s Sleep Disorder Research and Treatment branch in Chicago. Her research in the 1950s and 1960s included experiments involving the association between dreaming and rapid eye movement sleep, or REM sleep. In her 2010 book, The Twenty-four Hour Mind, she noted “sleep is a built-in physician and dreams an internal psychotherapist; that good sleep rests and restores our weary bodies and that good dreams temper our emotional responses to new experiences.”
Other researchers, such as Dr. Matthew Walker, director of the Center for Human Sleep Science at University of California, Berkeley, suggest that dreaming is “like overnight therapy” because during REM sleep, the brain doesn’t process the “flight or fight” stress response chemical noradrenaline. Yet essential emotional and memory functions freely engage. Without noradrenaline, it’s easier to “re-process upsetting memories in a safer, calmer environment.”
According to additional studies, it’s possible dreaming helps us store memories more effectively and, to Križan’s point, becomes a cleansing process, which allows our brains to retain what’s necessary and discard the rest. If you consider the brain as a massive computing system (which it is), perhaps dreaming might be the equivalent of clearing the history of your internet browser while keeping important tabs bookmarked for later.
More recently, in 2021, Dr. Ken Paller, director of the Cognitive Neuroscience Lab at Northwestern University, released findings from a team of international research collaborators that successfully communicated with participants who were in a lucid dream state — that is, actually alert enough to be aware they were still dreaming. The discovery expands on a theory that we can somehow use this ability for enhanced learning and problem-solving.
If you’re curious about this process, the team developed an Android app so you can try it at home.
What Is A Standard Dream?
Križan says a typical dream usually takes place in a mundane setting with familiar characters, although a mixing of time and place is common. “Also, most dreams are somewhat negative, and focus on anxiety-provoking events,” he adds. Why is this? Križan says one prevailing theory is that this narrative framework helps us anticipate unforeseen problems.
For example, in 2021, researchers studied the connection between dreaming and key areas of the brain instrumental in processing emotions such as anxiety, fear, and threat. Their findings, according to Geneva-based researcher Lampros Perogamvros, “reinforce a neuroscientific theory about dreams: we simulate frightening situations while dreaming in order to better react to them once we’re awake. Dreams may be considered as a real training for our future reactions and may potentially prepare us to face real life dangers.”
10 Different Types Of Dreams
While there’s really no way of knowing how many dreams we have each night (although researchers have tried to estimate them), the following seem to be the most universal dream types.
The American Psychological Association (APA) defines daydreaming as “a waking fantasy, or reverie, in which wishes, expectations, and other potentialities are played out in imagination.” Almost all of us do this for one reason or another. In fact, the APA suggests that up to one-third — and in some cases, one-half — of our waking thoughts are daydreams.
These types of dreams are a little harder to pin down, as it depends on how you personally want to interpret the experience, but they’re typically considered very vivid, memorable dreams. Dream interpretation enthusiasts think of epic dreams as profound, with long-lasting repercussions and life-changing potential. Conversely, scientists state that epic dream disorder is “relentless, neutral-content ‘epic’ dreaming without emotionality that is experienced to occur throughout sleep.” Simply put, individuals dream excessively of doing unrelenting, exhausting — often mondane —tasks and wake up feeling incredibly tired the next morning as a result.
False Awakening Dreams
Ever feel as though you’re going through your morning routine — taking a bathroom break, starting the tea kettle, letting the dog out — only to discover you were dreaming? This is a false awakening, which is common as you transition from REM sleep. Researchers also find it’s frequently associated with lucid dreaming.
A small percentage of individuals have the ability to lucid dream, which is when a person is between dream and wake states of consciousness. In some instances, they have the awareness and the ability to actually control the narrative of their dream or communicate in that state. It may be possible to train yourself to lucid dream, though the task would no-double take discipline and practice.
According to the APA, a nightmare is “a frightening or otherwise disturbing dream in which fear, sadness, despair, disgust, or some combination thereof forms the emotional content.” Most of us wake up quite suddenly from nightmares. Often filled with vivid imagery and strong narratives, they’re actually a normal occurrence for most people unless they disturb daily life or sleep habits. Dr. Clara Hill, a therapeutic dreamwork researcher and author at the University of Maryland, developed a cognitive-experiential model of dream interpretation that’s often used in the treatment of nightmares.
Night terrors are also known as sleep terrors. The Mayo Clinic indicates that many people experience “episodes of screaming, intense fear and flailing while still asleep … and sleep terrors are often paired with sleepwalking.” They’re more common in children but usually stop in adolescence, although some adults have them, too. While some episodes last mere seconds, others can be a few minutes or longer.
There’s really not a lot of science yet to quantify the theory of progressive dreams. Anecdotal interpretations define them as a sequence of dreams with a seemingly continuous narrative unfolding nightly or sporadically, like reading a book or watching a series on TV.
The fascination with dreaming began with cultures all over the world divining a sense of purpose from predictions of the future. From the ancient Egyptians and Greeks to untold religious leaders to Freud and Jung, the idea of dream precognition is woven through human history. Again, anecdotally, this ability is real to some people.
Scientists frequently associate recurring dreams — usually repetition of the same type of dream or subject — with an unmet need or an unresolved issue. Sometimes recurring dreams can be more disturbing if an individual has trouble processing traumatic events while they’re awake.
An unusual condition known as REM rebound is often the cause of vivid, intense dreams. REM rebound is our mind’s response to being sleep deprived or excessively stressed. So when we’re asleep, we experience heightened brain activity, which creates more powerful imagery. Some people might also experience vivid dreams when struggling with high fevers.
Common Dream Themes
The Cleveland Clinic explains that key neurotransmitters, such as acetylcholine and dopamine, are more active when we’re dreaming, which is why the subject matter might be a little strange — you know, like when your brother is totally a meerkat in a Star Trek officer’s uniform riding a unicycle and chewing bubble gum. Some studies indicate that a spike in dopamine contributes to hallucinations as well.
“Dreams are a time when our conscious brain does not engage in logical analysis, which allows us to accept often contradictory or bizarre dream settings — which would be impossible during waking consciousness,” Križan says. “There are different ways to organize types of dreams, but the most common themes around the world are childhood dreams of animals chasing you, teenage dreams of coming unprepared to or being embarrassed in school, and adult dreams about unexpected loss or failure.”
While there’s not a lot of science behind the meaning of these more popular themes, here are some dreams and interpretations:
- Arguments —There’s an unresolved issue or a big decision that needs rationalizing
- Being chased —You’re in “fight or flight” mode, struggling with something in real life
- Cheating — Often a reflection of relationship issues regarding communication and trust
- Crashing a car —You’re feeling out of control or perhaps trying to process a traumatic event
- Drowning — Feeling overwhelmed, repressing emotions, or physically having trouble breathing while sleeping
- Dying/death — Either it’s actual grief processing or there’s the potential for change in your future
- Failing exams — As the brain tries to process excessive information, you might be worried about how well you’re handling your responsibilities
- Falling — You feel a lack of control in life or a particular situation
- Flying — Either you feel free and liberated, or you long to escape current responsibilities
- Nudity — More than 70 percent of people have naked dreams, frequently associated with anxiety and “exposed” vulnerability
- Pregnancy/giving birth — Multiple meanings, from exploring creativity or a new idea to expanding relationships
- Teeth falling out — We’ve finally come to this one! Often related to feelings of anxiety and/or not being able to communicate
- Unable to find a toilet — Also possibly related to anxiety, as well as worries in the real world or various insecurities about letting go of something or someone who no longer serves you
- Visits from a deceased friend or loved one — Sometimes a method to process grief over an actual loss or closure in an unfulfilling relationship
“The occasional bizarre nature of dreams always had me fascinated,” Križan says. “Plus the notion there is this entire side of conscious life that — once you add all the hours of dreaming together, most of which are forgotten — totals around seven years of a typical life.”
The Last Word From Sleepopolis
Whether you’ve experienced all types of dreams or only a few, it’s fascinating to learn just how much scientists are still trying to crack the code of what they mean, the various theories involving them, and how they impact our waking lives.
When not traveling, teaching yoga, or doing voiceover projects, Tracey is an editorial strategist and content developer for print, digital, and multimedia platforms. Based in the Midwest, she writes on various topics, from addiction science and sleep hygiene to better bonding with pets and interesting nonprofit and advocacy efforts. She also makes a rather snazzy blueberry pie.