How Dreams Become Nightmares
The night I totaled my car, I lay soaking in the tub, letting one image after another surface in my mind. A ton of metal and plastic crunching into a thick cement railing. Pieces of debris scattering the road. The hard-rock-playing police man with tattoo decorated forearms and a playboy cup warmer. After about an hour of the myriad of splintered memories replaying in my thoughts, I asked myself, why am I just laying here thinking about the same things over and over? In the same breath I answered myself, because if I don't, then I'll have nightmares about it.
In psychological terms, I believe I was "processing" or "working through" the experience, and if I had not, then my unconscious would attempt to do it in my sleep.
I've had my share of frightening dreams in my life, some of them recurring nightmares that took me years to shake. A recent experience gave me a new understanding of what might be happening when we sleep.
After having surgery on my feet my toe was very sore. All day I consciously kept it perfectly still to avoid feeling any pain. At night however, I would wake up almost screaming from sharp pain in my toe. After three or four of these occurrences I realized what my body was doing. As soon as I fell asleep, my body tried to stretch my foot, which I had kept rigid all day. My mother spoke of a similar experience after she broke her knee; she would wake to her body stretching her leg as far as it could, when she had been careful to keep her leg perfectly still while she was awake.
If we do not allow ourselves to come to terms with frightening or stressful experiences, if we lock them out of our daily thoughts, then they will surface again when our guard is down. Acknowledging our experiences in a nonjudgmental way: "What happened was frightening, but I survived and it's time to move on" might help our minds accept what happened. I believe associating memories with a strong emotion, like fear, anger, or guilt is what causes reoccurring nightmares. When a nightmare is so frightening that it causes new trauma, those issues are not resolved, and possibly made worse.
My advice for someone suffering from very vivid nightmares: let your mind relax and let the thoughts or images evoked by your dreams to surface. Accept them for what they are "That was a painful experience or stressful situation, but I survived it. I am stronger from living through it and I don't have to be afraid any more."