The question of why we dream has fascinated philosophers and scientists for thousands of years. Despite scientific inquiry into the function of dreams, we still don’t have a solid answer for why we do it. While much remains uncertain about dreaming, many experts have developed theories about the purpose of dreams, with new empirical research providing greater clarity.



According to the activation synthesis model of dreaming, circuits in the brain become activated during REM sleep, which triggers the amygdala and hippocampus to create an array of electrical impulses.This results in a compilation of random thoughts, images, and memories that appear while dreaming.

When we wake, our active minds pull together the various images and memory fragments of the dream to create a cohesive narrative.

In the activation-synthesis hypothesis, dreams are a compilation of randomness that appear to the sleeping mind and are brought together in a meaningful way when we wake. In this sense, dreams may provoke the dreamer to make new connections, inspire useful ideas, or have creative epiphanies in their waking lives.


According to the information-processing theory, sleep allows us to consolidate and process all of the information and memories that we have collected during the previous day. Some dream experts suggest that dreaming is a byproduct, or even an active part, of this experience processing.

This model, known as the self-organisation theory of dreaming, explains that dreaming is a side effect of brain neural activity as memories are consolidated during sleep.During this process of unconscious information redistribution, it is suggested that memories are either strengthened or weakened. According to the self-organization theory of dreaming, while we dream, helpful memories are made stronger, while less useful ones fade away.

Research supports this theory, finding improvement in complex tasks when a person dreams about doing them. Studies also show that during REM sleep, low-frequency theta waves were more active in the frontal lobe, just like they are when people are learning, storing, and remembering information when awake.

Dreams Reflect Your Life 

Under the continuity hypothesis, dreams function as a reflection of a person’s real life, incorporating conscious experiences into their dreams.

 Rather than a straightforward replay of waking life, dreams show up as a patchwork of memory fragments.

Still, studies show that non-REM sleep may be more involved with declarative memory (the more routine stuff), while REM dreams include more emotional and instructive memories.In general, REM dreams tend to be easier to recall compared to non-REM dreams.

Under the continuity hypothesis, memories may be fragmented purposefully in our dreams as part of incorporating new learning and experiences into long term memory.Still, there are many unanswered questions as to why some aspects of memories are featured more or less prominently in our dreams.


Many other theories have been suggested to account for why we dream.

  • One theory contends that dreams are the result of our brains trying to interpret external stimuli (such as a dog’s bark, music, or a baby’s cry) during sleep.
  • Another theory uses a computer metaphor to account for dreams, noting that dreams serve to “clean up” clutter from the mind, refreshing the brain for the next day.
  • The reverse-learning theory suggests that we dream to forget. Our brains have thousands of neural connections between memories—too many to remember them all—and that dreaming is part of “pruning” those connections.
  • In the continual-activation theory, we dream to keep the brain active while we sleep, in order to keep it functioning properly.



Relatively rare dreams where the dreamer has awareness of being in their dream and often has some control over the dream content. Research indicates that around 50% of people recall having had at least one lucid dream in their lifetime and just over 10% report having them two or more times per month.

It is unknown why certain people experience lucid dreams more frequently than others. While experts are unclear as to why or how lucid dreaming occurs, preliminary research signals that the prefrontal and parietal regions of the brain play a significant role.


Experiences which are stressful show great frequency in our brain. Stress dreams may be described as sad, scary.

Experts do not fully understand how or why specific stressful content ends up in our dreams, but many point to a variety of theories, including the continuity hypothesis, adaptive strategy, and emotional regulation dream theories to explain these occurrences. Stress dreams and mental health seem to go hand-in-hand.

  • Daily stress shows up in dreams: Research has shown that those who experience greater levels of worry in their waking lives and PTSD report higher frequency and intensity of nightmares.
  • Mental health disorders may contribute to stress dreams: Those with mental health disorders such as anxiety, bipolar disorder and depression tend to have more distressing dreams, as well as more difficulty sleeping in general.
  • Anxiety is linked to stress dreams: Research indicates a strong connection between anxiety and stressful dream content.These dreams may be the brain’s attempt to help us cope with and make sense of these stressful experiences.


While there are many theories for why we dream, more research is needed to fully understand their purpose. Rather than assuming only one hypothesis is correct, dreams likely serve a variety of purposes.

Knowing that so much is left uncertain about why we dream, we can feel free to view our own dreams in the light that resonates best with us.

If you are concerned about your dreams and/or are having frequent nightmares, consider speaking to your doctor or consulting a sleep specialist.