To dream that you have a blister suggests that some minor problem is draining your energy and time.
To dream that you got the blister from hard labor means you need to make more effort to overcome your little problems.
To dream that you got the blister from a burn, suggests an emotional or relationship problem. Where the blister is located is also important.
If the blister is on your hand, you are having issues related to power and your abilities.
If the blister is on your face, this relates to issues involving your identity and self-image.