A dream can recur because the matter involved is somehow is important, urgent, or difficult for your subconscious mind to process. It can indicate unresolved emotions or other unfinished business from a real-life situation, and some inner process or outer action is often necessary to resolve the situation in order for the dream to stop recurring. Also, consider whether the same thing triggered the dream each time (such as having a nightmare about spiders after each time you encounter a feared situation in real life).
Inner dynamics of recurring dreams can include: