Most people associate hives โ€” the raised, puffy welts on your skin that spread when scratched โ€” with an allergic reaction, but there are a number of factors that can cause them. One of these factors is stress, and if you find yourself breaking out in hives without another likely cause, itโ€™s possible stress is to blame.

We spoke to Mary Stevenson, an assistant professor of dermatology at NYU Langone, to learn more about what causes stress hives, and what to do โ€” and what not to do โ€” if you have them.