Dreams aren't always as they appear. They are typically symbolic. There's a Dreams and Interpretations sub forum, you may want to look into, here on PC.

I sometimes write down my dreams in a journal and use a dream moods site and books to analyze the symbolism and see what's bothering me on a subconscious level.

For instance to see a shark, represents anger. The color red, passion. There's symbolism for amputation, that doesn't resound off the top of my head.