What is actually happening when we dream?

Thanks invite. .......... I agree answer ghada

it is the soul leaving the body exploring the world according to the narrations. read the religious books and you can read 

IMAGE WITHOUT EXTERNAL STIMULUS AND ENERGY CONSERVATION.

Thank you Ms. Farhana for a good topic.

Actually, for hundreds if not thousands of years dreams have been studied and attributed meanings. Some have said there is an evolutionary reason whilst others say it is our brains way of assimilating the day's information. 

For me personally Dreaming is a God willing! I believe in . I have had recurring nightmares as a child that I still remember now, and at times have had dreams so real and vivid that I cannot shake the feelings and emotions felt for hours, sometimes days.

Neverthless, I would like to know what actually happens to us and our brains when we dream; particularly anxiety dreams or nightmares, and why?

Why we sleep has been a matter of heated discussions among neuroscientists. There are a plethora of theories but there appears to be no strong consensus.As Russel Foster, a neuroscientist that presented at TED, has outlined, we need to spend a third of our lives asleep for several reasons from which are:

• Energy conservation, but this wasn't convenient as we only save the amount of calories found in a hotdog when we're asleep, pretty useless.
• Restoration, and getting ready for a new day. And this one is actually supported by strong evidence as scientists have found out that some genes related to restoration and metabolic pathways are turned on only during sleep.
• Brain processes and memory consolidation. And actually this is the strongest theory of all, as it was found that sleep-deprived people find it more difficult to learn new skills and to come up with creative solutions to problems. Next time you're facing a difficult situation, just go get some sleep.

So what happens when we're asleep ? our brains do the most amazing stuff and we're not even aware of it.

 Here's a scientific explanation :

Basically, Dreams are subconscious thoughts.  Nonetheless, whether our thoughts are experienced subconsciously or consciously, they are all simply that— only our thoughts!  Dreaming is a product of our imperfect brain’s inability to control our subconscious mind.  Our dreams are produced by an imperfect brain.  Our dreams are a disconnected and often random attempt of our conscious mind (our mortal brain) seeking to make sense of the subconscious.Dreams are an inescapable part of how our imperfect brain functions.  This is because the brain (our imperfect body) cannot consciously access or control the subconscious.  When we dream, we are not completely in a subconscious state.  Our brain is working hard during a dream as well as are the rest of the sensory systems of the body.  As we dream, our conscious mind tries to make sense out of the dream, causing an expenditure of energy that takes away from a good night’s sleep.However, those who take their dreams too seriously often become more out of touch with reality than those who do not. Dreaming is simply the random recollection of stored memories from our physical brain that our conscious mind is attempting to organize into reasonable and recognizable experience. Unless some outside manipulation is taking place, such as hypnosis, all dreams materialize from the random, fragmented parts of our actual experiences in our recent or long ago past.  When our imperfect brain attempts to organize our memories of past experiences into something we can consciously understand, our dreams become subconscious compilations of completely unrelated instances we have a hard time explaining or figuring out.  We dream in an unconscious state. Dreaming is an involuntary mental process that begins in our mind randomly.  The dreams we have in a subconscious state can be compiled experiences of unrelated incidents (or even fantasies) that would never happen in reality.  What we are dreaming is simply recollection of our experiences stored in our subconscious memory.  It is this “memory” that stores all of our experiences and defines us as individuals based on these past experiences.Because our imperfect brain only allows us to remember fragments of our past experience, it tries to make sense of the memories affecting it when we are asleep.  This becomes our dreams. Most people have similar dreams.  As we are dreaming, our ability (mental capacity) to reason is greatly inhibited, along with many of the other functions of our imperfect body; therefore, we can dream some very weird and nonsensical things.  Dreaming is a product of our imperfect brain’s inability to control our subconscious mind.  When this occurs, the person’s capability to reason is not fully utilized and therefore, it cannot organize the memories into reasonable experiences.  Thus, the fragmented and nonsensical experiences associated with dreaming are created.Although dreams are not necessary, they are an inescapable part of how our imperfect brain functions.  This is because the brain (our imperfect body) cannot consciously access or control the subconscious.  When we dream, we are not completely in a subconscious state.  Our brain is working hard during a dream as well as are the rest of the sensory systems of the body.  As we dream, our conscious mind tries to make sense out of the dream, causing an expenditure of energy that takes away from a good night’s sleep.Those who take their dreams too seriously often become more out of touch with reality than those who do not. Dreaming is simply the random recollection of stored memories that our conscious mind is attempting to organize into reasonable and recognizable experience. Dreams materialize from the random, fragmented parts of our actual experiences in our recent or long ago past.  When our imperfect brain attempts to organize our memories of past experiences into something we can consciously understand, our dreams become subconscious compilations of completely unrelated instances we have a hard time explaining or figuring out.

I couldn't think of the answer or any experience to relate or answer your question because I'm sleeping at the time of dreaming (smiled).