Almost everyone has had a blister at some point in their life, whether it’s a foot blister caused by an ill-fitting shoe, a blister on their hand from a long day of working in the yard or a blister that appears after getting burned. Of course, there are different types of blisters because there are a variety of things that cause them.
A blister is a small fluid-filled pocket, or bubble, that occurs when the outer layers of skin are damaged. The fluid in the pocket is typically what is known as serum. Serum is the watery fluid left over after red blood cells and blood clotting agents have been removed from your blood. (Sometimes blisters can actually be filled with blood. These are called blood blisters and you can learn more about them below.) The clear serum in your blister has a purpose — it fills in under the damaged layer of skin in order to create a soft barrier between the inflicted area and the fragile tissue underneath. This means your body has its very own blister treatment: this natural process allows the damaged skin to heal.