Why Do We Dream?

By Deluxe Sleep · Published on 28 July 2026

Why Do We Dream?

So that we can get through everyday life fit and healthy, we need restful sleep. But another component is important for a good night's rest: dreams. These often bizarre and highly imaginative experiences appear to us night after night. Even when we no longer remember them. But why is that, and what actually are dreams?

Dreams – What Are They, and Why Do We Dream?

Today's modern definition is: dreams are subjective experiences that arise during sleep. On average, every person dreams for about six years of their life. Whether they remember it or not. The question of why we dream, however, is still a mystery. Before modern science could research this topic, humanity relied on conjecture. That is why many cultures believed for a long time that dreams were messages from the gods. Besides messages, dreams are also seen as a source of inspiration. For instance, the singer Paul McCartney came up with the melody for the song "Yesterday" in a dream. Modern science tries, through research and studies, to better explain the function of dreaming. One study states that nightly dreaming processes emotions. Another, conducted by brain researchers Giulio Tononi and Chiara Chirelli, indicates that during sleep the brain breaks down weak synaptic connections again that were created during the day. A kind of "tidying up of the brain" takes place, in which the important is separated from the unimportant. This process is said to be important for mental health. The psychologist Rubin Naiman also pursues the health angle. He is convinced that sufficient dreaming points to healthy sleep. Most of the dreams we remember are generated during the REM sleep phase. Anyone who does not remember their dreams has probably not gone through enough REM sleep phases and is more susceptible to health problems.

REM Sleep: What Happens in the Brain When We Dream?

Many people mistakenly believe that the brain calms down at night. Studies have shown, however, that the brain is almost as active during sleep as it is during the day when we are awake. During the night we pass through different sleep phases, which also determine our dreams. In the best case, these phases occur one after another and repeat several times over the course of the night. First, we glide from wakefulness into the falling-asleep phase and then into the light sleep phase. Here, our dreams are choppy, fragmented, and mostly full of impressions from the day just passed. These dreams are also not linked to emotions or deeper feelings. This is followed by the deep sleep phase and then the REM phase, or REM sleep. Now dreams are perceived as especially intense. The term "REM" derives from the English "Rapid Eye Movement," which occurs behind closed eyes during this sleep phase. In this phase, breathing is irregular, and pulse and blood pressure fluctuate. During this time, there is no absolute boundary between dream consciousness and waking consciousness. The muscles (apart from the heart, diaphragm, and eye muscles) are also paralyzed, aside from the occasional twitch. While dreaming, the amygdala, which is responsible for processing emotions and feelings, is more active. That is why dreams are often emotional.

During sleep we pass through sleep phases that repeat several times during the night.

Nightmares and Lucid Dreaming: The Different Types of Dreams

The most common dreams are probably nightmares or anxiety dreams, recurring dreams, and lucid dreams. Anxiety dreams or nightmares in particular leave a deep imprint on people, since they are often fed by negative feelings we experience while awake. Recurring dreams are also closely linked to emotions. If a person has been preoccupied with a problem for some time, for example, it can lodge itself in the subconscious and manifest as a recurring dream.

While dreaming, many people are often unable to distinguish between reality and fiction, nor can they exert any control. The one exception is lucid dreams. Anyone who has lucid dreams can consciously perceive the dream as such in the moment and, up to a certain point, direct it themselves. The good news: it is indeed possible to learn this kind of dreaming. There is no universally valid recipe for achieving this. There are, however, some exercises which, if practiced regularly, can help. One of these exercises consists of engaging intensively with your own dreams and actively thinking about a particular topic or experience before going to bed. This stimulates the brain, and the likelihood of dreaming about what you were just thinking about increases. After waking up, it is important to immediately write down the still-fresh memories of the dream. This process should be repeated until an awareness for dreaming develops.

Facts About Dreaming

Many mysteries still surround dreaming. For instance, scientists do not yet know why many people no longer remember their dreams shortly after waking. What has been discovered, however, is that animals are also capable of dreaming. In dogs, for example, this shows up through whimpering, rapid running movements, and small barks. Furthermore, studies have shown that not all people dream in color. About 20% dream in black and white. Blind people who have been unable to see since birth mostly dream in sounds, touch, or smells. But no matter who dreams how, the fact is that we all do it.

Even if we no longer remember it, every one of us dreams.

Source: This article is based on a piece from the BICO sleep blog (bico.ch). The research findings, product developments, and test results mentioned in it come from BICO or from the respective third parties named.