There are a lot of reasons why a person might have horrific or scary dreams. The most common one is that they just witnessed something horrific, and the most common thing to randomly witness is a TV show or a movie. If you saw a horror movie then it might not be hard to describe why you ended up having a dream about dismemberment or about being dismembered. Another possibility is that you heard a scary story or read one in a book. People do not generally come into contact with dead bodies on a daily basis, so you certainly did not draw the idea of death or dismemberment from something that you saw in everyday life unless you are a police officer working on a particularly brutal murder or a hospital or morgue worker dealing with victims of some bizarre crime. Hopefully for you a dream like this can be explained away that easily, otherwise the next few modes of interpretation might seem more brutal or even more terrifying.
If you have a dream in which you see yourself and you have been dismembered in some way then you need to pay attention to the part of you that was dismembered. You need to think about what it means to you to have your arm or leg taken away. If you have a dream in which your arm has been removed it means that you feel like you cannot act in a certain situation. Your life has thrust you into a position in which you want to cut but you can’t because you don’t know how. Either that or everything you try just seems to bounce back at you not working. You want to be able to help but you just can’t.
To dream that your leg has been taken from your body means that there is somewhere that you want to go or some goal that you want to achieve, but the path to getting to this goal has somehow been cut off for you. This does not mean that you failed to get there; it means that the path has changed all of the sudden and now you are the one that has been tasked with a way of trying to find out how to get back on that path the way it once was before. You need to find your way back to that position if you want to succeed at your goal. The key here is to not get so disheartened that you just quit entirely. No, you want to make sure that you try as best you can to get there even when the odds are stacked against you and you have no idea how you are supposed to make it. This is the way the dream world works, and it is what you are going to have to learn to work with if you know what’s good for you. This is what the dream is all about and to put it into perspective, you need to relax, first and foremost.