What causes dreams or nightmares?

Hi,
Dreams (and nightmares) are the sub-conscious telling you what you might possibly be thinking about.
Sometimes, if you think about something all day long, then the next day, you might wake up, remember parts of a dream about it. The sub-conscious lets it out in the form of dreaming.
Nightmares come from maybe a bad experience, and could be from long ago.
They normally don't mean anything, and can't predict the future. It's only indicating what you might be thinking about.
I hope this helps some.

Here is a link:
http://kidshealth.org/kid/feeling/th...ightmares.html
I don't know if you are a "kid", but the link explains both dreams and nightmares very well; both for kids and adults.

Hi,thanks for asking about dreams:

Sleep pattern consist of two phases REM sleep(rapid eye movement)
And nonREM sleep
While in the middle of the night we goes into the phase from non REM to REM sleep and this is the phase when we see dreams
You have heard of ECG (electrcardiogram) but we do an EEG (Electro encephalogram) of the patient to know about the pattern of brain waves of the patient
During day time normal person have a alpha wave but during sleep they changes to the pattern of beta wave
There are many theories abou it
Like during sleep brain secrete some hormones like groth hormones putitory gland harmones which give cause dreams + hallucination

Other theory beside medical science for the dreams is that during dreams we leave our body and have a astral projection in the etheric world
Its totally a different theory and if some one want to know about the astral projection or to induce that ability please ask me and I will give the details in another time

Cheers

drali77

Don't forget to rate this answer by pressing the right corner button
Thanks

Nightmares can be caused by several different things. One thing to mention that even certain foods or even certain medications can actually trigger nightmares.

Joe