Rest easy, the answer is yes: Everybody dreams.

Whether we recall what we dream, whether we dream in color, whether we dream every night or just every so often — these questions have more complicated answers. And then there’s the really big question: What do our dreams actually mean?

These questions have captivated researchers, psychoanalysts, and dreamers for centuries. Here’s what current research says about the who, what, when, how, and why of our dreams.

Dreaming is a period of mental activity that happens while you’re sleeping. A dream is a scenic, sensory experience involving images and sounds and occasionally smells or tastes.

Dreams can even transmit sensations of pleasure or pain. Sometimes a dream follows a narrative storyline, and sometimes it’s made up of seemingly random images.

Most people dream for around 2 hours every night. At one time, sleep researchers thought people dreamed only during rapid eye movement (REM) sleep, a period of deep sleep during which the body carries out important restorative processes. But more recent research has shown that people dream in other stages of sleep, too.

Researchers have been analyzing the biological, cognitive, and emotional purposes of dreams for many years. Here are two of the most important and well-researched reasons you need your dreams.

Dreams can help you consolidate memories and process emotions

Researchers have found important links between highly emotional life experiences and strong dream experiences. They are both processed in the same regions of the brain and along the same neural networks. Replaying powerful life experiences is just one way dreams can help us process emotions.

It’s also possible that dreams create a kind of problem-solving rehearsal that may boost your ability to handle real-life crises.

Another theory is that dreams — especially strange ones — may help shrink scary experiences to a manageable “size” by placing fears side by side with really bizarre dream images.

Dream sleep may help you process excess learned information

New research seems to indicate that while we are in REM sleep, the stage of sleep when most of our dreams are produced, the brain is sorting through what we learned or experienced during the day.

In a mice study at Hokkaido University in Japan, researchers tracked the production of melanin concentrating hormone (MCH), a molecule that sends messages to the brain’s memory center in the hippocampus.

The study found that during REM sleep, the brain produces more MCH and that MCH is linked to forgetting. Researchers concluded that chemical activity during dream-intensive REM sleep helps the brain let go of excess information gathered during the day.

The short answer is that people who don’t remember their dreams could easily conclude that they’re just not dreaming. Not remembering dreams is not unusual. A large 2012 study of more than 28,000 people found that it’s more common for men to forget their dreams than for women.

But rest assured, even if you never remember having a dream in your entire life, it is very likely that you are dreaming nightly.

In one 2015 study, researchers monitored people who didn’t recall their dreams and found that they displayed “complex, scenic and dreamlike behaviors and speeches” while they slept.

Some evidence suggests that as we age, our ability to remember our dreams decreases, but whether we actually dream less as we age or whether we recall less because other cognitive functions are also declining is not yet known.

The answer to this question, researchers believe, is complex. Older studies found that people who lost their vision after the age of 4 or 5 can “see” in their dreams. But there is some evidence that people born blind (congenital blindness) may also have visual experiences while they dream.

In 2003, researchers monitored the sleeping brain activity of people born blind and people born with sight. When the research subjects woke up, they were asked to draw any images that had appeared in their dreams.

Although fewer congenitally blind participants remembered what they dreamed, those who did were able to draw images from their dreams. Similarly, the EEG analysis showed that both groups experienced visual activity during their sleep.

More recently, a 2014 study found that people with both congenital blindness and late blindness experienced dreams with more vivid sounds, smells, and tactile sensations than people with sight did.

Dreams and hallucinations are both multisensory experiences, but there are several well-researched differences between the two. The major difference is that dreams happen when you’re in a sleeping state, and hallucinations happen when you’re awake.

Another difference is that a dream is usually separate from reality, whereas hallucinations are “overlaid” onto the rest of your waking sensory experience.

In other words, if a hallucinating person perceives a spider in the room, the sensory information about the rest of the room is being processed more or less accurately, alongside the image of the spider.

Any pet owner who has watched the paws of a sleeping dog or cat seem to chase or flee would answer this question with a firm yes. Sleep researchers agree, at least as far as most mammals are concerned.

Yes, certain themes do appear to recur in people’s dreams. Countless studies and interviews have explored the subject of dream content, and the results show:

  • You dream in first person.
  • Bits of your lived experience make up the dream, including your concerns and current events.
  • Your dreams don’t always unfold in logical sequences.
  • Your dreams often involve strong emotions.

In one 2018 analysis of over 1,200 nightmares, researchers found that bad dreams usually involved being threatened or chased, or loved ones being hurt, killed, or endangered.

You might not be surprised to learn that monsters show up in children’s nightmares, but it’s interesting to note that monsters and animals still show up in bad dreams well into the teenage years.

Some people are able to induce lucid dreaming, which is a vivid sleeping experience during which you’re aware that you’re in a dream. There are some indications that lucid dreaming may help people who have experienced trauma or who have been diagnosed with post-traumatic stress disorder (PTSD).

If you have nightmares that disrupt your sleep and your emotional life, imagery rehearsal therapy could help. Your doctor may also be able to prescribe a blood pressure medicine called prazosin (Minipress).

All people — and many animals — dream when they sleep, though not everyone later remembers what they dreamed. Most people dream about their life experiences and concerns, and most dreams incorporate sights, sounds, and emotions, along with other sensory experiences like smells and tastes.

Dreams can help you process what’s going on in the larger world and in your own personal life. Some people have had success controlling trauma-induced nightmares with medication, imagery rehearsal therapy, and lucid dreaming.

Because dreams serve important cognitive and emotional purposes, it’s a very good thing that we experience dreams while we sleep — even if we forget them when we wake.