Understanding Blisters -- Symptoms

Medically Reviewed by Sabrina Felson, MD on April 21, 2021

What Are the Symptoms of a Blister?

A blister is a bubble of skin filled with clear fluid, ranging from pinpoint size to more than an inch in diameter. They are different than pustules, which contain thicker, yellow-white material called pus.

Depending on the cause, blistering may be accompanied by pain, redness, or itching.

Call Your Doctor About a Blister If:

The blister was caused by contact with a chemical -- or if you have an autoimmune blistering disease. Other reasons to seek medical advice is if you have multiple blisters, or they progress in number and location, or if you can’t figure out why you are getting them.