The dust in my house is affecting my health?

My house is so cluttered up with crap and there is dust everywhere. I have been sneezing alot recently and I have asthma. I am getting sick of people shouting "swine flu!" every time I sneeze it's embarring. I do not think that it is a time of year thing I think that it is because of the state my house is in. My parents don't really do anything about it (they don't have much time to be fair) I vacuum my room all the time but the dust just keeps coming back. I went to stay with a relative for 4 days and I never sneezed once. What can I do about this?