How will i know what does an igg and igw blood test, test for?

Hmmm.: I think you mean igg and igm (i'm not sure what igw testing is for), but igg and igm are antibody tests that evaluate for evidence of either recent or long-ago exposure to an agent (virus/bacteria, etc) that produces an immune response. Igm is positive in the presence of a "new" exposure, it's a primary response, that is usu. Positive for several months, then 'converts' to igg which remains pos lo.