While scientists have been studying dreams for years, the images that appear while we snooze are still incredibly misunderstood.

When asleep, our minds are active, creating stories and images that can be either vivid or fleeting; nonsensical or seemingly prophetic; terrifying or absolutely mundane.

Why do we dream? We may not have definitive answers, but there are several types of dreams and themes, and different factors that cause these dreams to occur.

According to the National Sleep Foundation, we typically dream about four to six times per night. There’s no way, you might be thinking, but that’s only because we forget more than 95 percent of all dreams.

Dreaming happens throughout the night, but our most vivid and often remembered dreams happen during rapid eye movement (REM) sleep.

A dream can be influenced by what we’re thinking about before we go to sleep, or what we’ve experienced in our waking day. Dreams can also bring to light what we’re avoiding thinking about or our anxieties.

According to research, 65 percent of the elements of dreams are associated with your experiences while awake.

If you’ve got job stress, your dreams might take place at work or involve your co-workers. If you just went on a date, your dream might be full of romance, or on the flip side, heartbreak, if you’re having anxiety about dating someone new.

A “standard” dream will vary depending on the individual, but below are some features of dreams:

  • Most dreams are predominantly visual, meaning that images are at the forefront of dreams, rather than other senses like smell or touch.
  • While most people dream in color, some dreams are entirely in black and white.
  • The less stressed you are, the more pleasant your dreams may be.
  • Dreams can be very strange — and that’s totally normal.
  • Your mood, events in the news, pain, violence, and religion may all influence your dream’s subject.

Nightmares are dreams that are scary or disturbing. Almost everyone has nightmares from time to time and there’s not always a good reason why.

Some potential causes of nightmares include:

  • watching or reading something scary
  • sleep deprivation
  • eating right before bed
  • medication side effects
  • having a fever or being ill
  • sleep disorders, such as sleep apnea, nightmare disorder, or narcolepsy

People experiencing a lot of stress or who have mental health conditions like anxiety disorders may experience dreams that are more frightening. Up to 71 percent of people with post-traumatic stress disorder (PTSD) may experience nightmares, which can be recurring if not treated.

One study found that the three most common nightmare themes involved:

  • death or dying
  • physical violence
  • being chased or hunted

Night terrors are a type of sleep disorder that’s more common in children than adults.

When someone has a night terror, they wake up terrified but may only have a vague idea of what they dreamed about. Most of the time, they don’t remember dreams from the night terror.

In a night terror, a person can wake up:

  • screaming
  • kicking or moving violently, even jumping out of bed
  • sweating
  • breathing hard
  • with a racing heart rate
  • disoriented and unsure where they are or what’s going on

Night terrors aren’t technically a type of dream, but a sleep disorder.

What’s the difference between a nightmare and night terror?

  • Night terrors most commonly happen during non-REM sleep, while nightmares typically happen during REM sleep.
  • Night terrors are much more common in children, who experience more non-REM sleep, while nightmares can affect those at any age.
  • Nightmares are often vividly recalled dreams while night terrors are easily forgotten.

Lucid dreaming means you’re aware that you’re dreaming while you’re in the dream. Like most dreams, it often happens during REM sleep.

Most people don’t have frequent lucid dreams, though some research reports that 55 percent of people experience it at least once in their lives.

Sometimes you can control a lucid dream if you have practice. This can help you control your dreams, especially if you tend to have recurring dreams or nightmares.

Daydreams

The main difference between a daydream and all other types of dreams is that you’re awake during a daydream.

Daydreams occur consciously, but you may still feel like you’re not fully awake or aware of your surroundings. If someone catches you daydreaming, they may say that you look “zoned out” or lost in thoughts.

Daydreams usually involve other people, whether real or imagined. Some research has shown that daydreaming about people you know predicts positive well-being while daydreaming about people you aren’t close to can predict more loneliness and worse well-being.

Recurring dreams

Recurring dreams are dreams that repeat more than once. They often have themes such as confrontations, being chased, or falling.

You can have neutral recurring dreams or recurring nightmares. If you have recurring nightmares, it may be due to an underlying mental health condition, substance use, or certain medication.

Common themes in recurring dreams involve:

  • being attacked or chased
  • falling
  • being frozen with fear

False awakenings

False awakenings are a type of dream occurrence where a person believes they’ve woken up but actually haven’t. If you’ve ever found yourself dreaming that you woke up, but it was actually a part of the dream, this is a false awakening.

False awakenings have been noted to occur alongside lucid dreams and sleep paralysis.

Healing dreams

While there’s not a lot of scientific information on healing dreams, they’ve been described as dreams that:

  • bring you balance or harmony
  • give you a sense of connection, meaning, or purpose
  • bring about reconciliation
  • leaves you feeling joyful or at peace

Prophetic dreams

Prophetic dreams are thought to be dreams that have foretold a future event. If you dream of something happening and then it occurs later, you may feel you’ve had a prophetic dream.

Historically, dreams were considered to impart wisdom or even predict the future. In some cultures today, dreams are still considered to be a way of receiving messages from the spirit world.

There’s no real way to tell if a dream is prophetic or not — it comes down to what you believe. Some believe that a prophetic dream is just your subconscious anticipating a particular outcome and having you dream it to prepare.

Vivid dreams

Vivid dreams are almost always associated with waking up during REM sleep when your dreams are most vivid and more easily remembered.

While we may consider any dream that we experience in REM sleep “vivid,” with vivid dreaming, it’s used to describe a particularly intense dream that felt very real. You may also remember your vivid dream a lot easier than a typical dream.

Anyone can have vivid dreams, but if you’re pregnant or particularly stressed, it may contribute to having one.

Have you had a dream about your teeth falling out, flying through the sky, or being chased? These are common themes that many people dream about.

Some of the most common dream themes are about:

Dreaming about specific things like this could mean many things, or as some researchers believe, be completely nonsensical. Interpretations will vary depending on the individual and how they’re doing in their day-to-day lives.

Dreams about falling or being chased may indicate experiencing anxiety or conflict, or even falling in love.

Dreams about teeth falling out have been interpreted as everything from stress and big life changes, to indicating dental health issues.

Losing teeth, being naked in public, and test taking may all fall under fear of embarrassment.

Just because we don’t always remember our dreams doesn’t mean we’re not dreaming. Everyone is doing it. Even people who were born without sight dream — their dreams are reportedly just composed more of the other senses, like sound, touch, and smell.

While we’re all dreaming while we sleep, there may be times when you’re more likely to experience certain types of dreams or remember them more often.

  • In childhood. While children may not necessarily dream more than adults, they’re more likely to experience certain types of dreams, like night terrors or nightmares, than adults.
  • During pregnancy. Sleep and hormone changes during pregnancy may be to blame for changes in dreaming. Those who are pregnant may experience more vivid or frequent dreams and even more nightmares. You may also be able to remember dreams better.
  • While grieving. Some research has found that dreams may be more vivid and feel more meaningful when you’re mourning. This can be a part of going through the grieving process.

If you’re experiencing extra stress or anxiety, have a mental health condition, or have experienced a traumatic event, you may also be more likely to have nightmares or vivid dreams.

Scientists don’t have all the answers on why we dream or why we have the types of dreams we have, but there are some clues.

Whether you’re having vivid dreams, nightmares, or lucid dreams, if your dreaming starts to interfere with getting enough sleep, or you believe there’s an underlying cause for your dream type, speak to a healthcare professional.