[bloak]

"You might have cancer" is an example of a sentence whose meaning can't easily be analysed in terms of "truth conditions" (https://en.wikipedia.org/wiki/Truth_condition). When used appropriately, the speaker has information which they believe the listener does not already have and which, in the opinion of the speaker, should cause the listener to increase their estimate of the probabiliy of them having cancer ... or something like that. So the appropriateness of the statement depends rather crucially on the context and on prior knowledge. That's why sentences with the word "might" tend to become infuriatingly meaningless when quoted out of context by journalists.