Hives, also known as urticaria, are a skin reaction that causes itchy welts. In many cases, hives are the result of an allergic reaction to something that a person has encountered or swallowed, such as certain medications, food, animal dander, pollen, or insect bites. However, hives can also be caused by other factors besides allergies, such as stress, tight clothes, exercise, illnesses, infections, excessive exposure to hot or cold temperatures, or irritation due to excessive sweating.
There are two types of hives: short-lived (acute) and long-term (chronic) . Acute hives are often an allergic reaction to something that a person has put into their body, like food, drink, or medication, or something that they have touched. Chronic hives, on the other hand, are welts that last for more than six weeks and return often over months or years, and their cause is often unclear.
If a person experiences severe hives or hives that last for more than a few days, they should see a healthcare provider. An allergist may want to conduct skin tests, blood tests, and urine tests to identify the cause of the hives. Once the trigger is identified, the person will likely be advised to avoid that trigger and products made from it.
