I've been trying to find an easy way of explaining this for years, but I usually end up giving an example: I have a fear of mice. Now, I am old enough to know better than to let that fear get to me, I understand mice, but that doesn't mean the fear has gone away. If a mouse comes through the house at night, and I hear it in my sleep, I will have a nightmare - not of a mouse, but of something much scarier, that has the scurrying qualities of a mouse, an intruder who gets onto my bed that I can't get off of me. This is my fear of what a mouse might do maginfied a hundred times! In this way the nightmare vents my fear.
A repeating dream is a message that our mind needs us to recognize, to figure out. The best way to do that is look past the details to what is basically happening in the dream. The dream stops when we either resolve the issue without realizing it in our daily lives, or we figure out the dream. You know the full details of your repeating dreams - look at them again. For years I had repeating dreams of aliens coming down to visit me, sometime a few at a time, sometimes hundreds, always frightening. One night in the middle of the dream I became lucid (conscious in the dream) and I said, "I know what you are now: my fear of the unknown." Just that little thing. The second I said that, the aliens disappeared and were replaced by a celebration that was almost like I'd won a million dollars! ;D
If you have repetitive dreams or dream symbols, I wouldn't worry. If something does come back, write it down when you wake up, then read it. You may be able to see what is basically happening in the dream, perhaps something as simple as a common fear. Then let it go.