Dreams are a universal phenomenon that span species, time and even place. Early civilisations thought of dreams as a medium between humans and the gods. In the third Millennium, BCE Mesopotamian Kings recorded and interpreted their dreams on wax tablets. A thousand years later, ancient Egyptians recorded their dreams in a dream book, trying to uncover their meanings by listing over 100 common dreams.

Dreams are made up of what you know and what you can imagine, basically everything that's going through your brain, reflecting what is going on in your waking life to your subconscious. REM (Rapid Eye Movement) sleep — the time in our sleep state when we dream — takes up 20 to 25% of our time asleep, and yet there is still no consensus amongst scientists on whether dreams are the product of random neurons firing or if there's something more going on behind closed eyelids.

What are our brains doing while we're asleep?

Metabolic clearance - while we're asleep, our brains are doing their best to clean our minds. This usually occurs in the amygdala and hippocampus. These areas are in charge of our emotions, senses and memories. It is the act of this clearing that triggers our brain signals and spikes impulses. It is the effort to give these sudden signals meaning that causes us to dream.

Memory and dreaming are intrinsically linked. Memories are what is used to make sense of the signals and impulses resulting from this activity.

When does dreaming occur?

When we dream this is mostly happening in the REM cycle of sleep. This is the period where our eyes are moving quickly in different directions and begins about 90 minutes after we fall asleep. You can also dream out of REM, but as this is a more active time during sleep, your dreams tend to be more intense.

Now, let's roll out the theories

As mentioned above, there is no consensus about what dreams really mean, however that hasn't stopped psychologists from theorising.

We dream to fulfil our wishes

This theory is brought to us by none other than renowned yet chaotic psychologist Sigmund Freud. He referred to the process of dreaming as 'a royal road to the unconscious.' His belief is that dreams are repressed conflicts or wishes. Freud thought of dreams as a gateway to understanding the unconscious mind which is why he spent a lot of his career studying the nature of dreams.

*It is important to remember that many of Freud's theories are fallible and therefore not to be taken at face value.

Threat simulation theory

This theory thinks of dreams as a defence mechanism to prepare us for threatening situations, equipping us to deal with difficult situations that we can work through in the safety of our slumber, rather than dealing with them for the first time in real life.

There are also critiques of this theory that argue that the content may be the result of selective memory and therefore emotionally charged, the nature of dreams are too bizarre to offer real simulation and nightmares can't be considered beneficial.

How do I interpret my dreams?

Dreams are just an extension of what is going on in your waking life, so if you want to decipher dream meanings, start with what you think about when you're awake.

If you start keeping a regular journal and a dream journal, you will begin to notice parallels between your dreams and your daily struggles and achievements.

Why do we have nightmares?

There are those types of spine-tingling dreams, known as nightmares that occur on the cusp of dreams and wake: nightmares. They usually occur as our body is preparing itself to re-enter the realm of the conscious, as our memories begin to integrate and consolidate inside our sleepy minds. Nightmares can occur for many reasons including stress, anxiety, irregular sleep and mental health disorders. The most commonly studied, however, is post-traumatic stress disorder.

In order to make nightmares stop, it all needs to stem from addressing the problem head-on in conscious life, through eliminating the stress or addressing traumas in your life.

What are common dreams?

Although we don't know what the meaning of dreams really are, it's still fun to speculate. Here are the five most common dreams and the possible meanings.

The Dream: You're falling into an abyss of nothingness

What it could mean: Those dreams about falling when you wake up just before you hit the ground from great heights. These dreams could be about feeling unsupported or insecure.

The Dream: You're being chased

What it could mean: In dreams where you're being chased, the chaser could represent a monster. As we all know from horror films though, that monster is probably a manifestation of something else. It could be a representation of being found out for an indiscretion, addiction or debt.

The Dream: Your teeth are falling out

What it could mean: This seems to be a fairly common one, although thankfully unfamiliar territory in my subconscious. This dream is all about anxiety coming through in the form of a dream. Dreams, where your teeth are falling out, are often connected to times of change and transition, and concern about one's appearance.

The Dream: You're flying

What it could mean: Ah the flying dream. That glorious time when you're up in the clouds, looking down at the world below, or at least some people feel that way about them. Others find them to be quite frightening. Tony Crisp, author of Dream Dictionary thinks that flying dreams can have a few different meanings. On the one hand, they can signify freedom and independence, and on the other, they could represent the need to flee or escape from the realities of your life.

The Dream: You're dying

What it could mean: Dreaming about yourself or a loved one dying is amongst the most common subject of dreams. A common interpretation of this kind of dream is fear of the unknown or anxiety about change. Another interesting take on this is if the dreamer has had children. Lauri Lowenberg, author of "Dream on It: Unlock Your Dreams, Change Your Life," believes parents could be wondering where the younger version of their children went, as they're mourning the passage of time.

There is so much more to learn about the fascinating phenomenon of dreams, ever heard of lucid dreaming?