How are hives (urticaria) and swelling (angioedema) diagnosed?
Your doctor can diagnose hives and swelling by looking at your skin. Allergy tests can help identify what’s triggering a reaction. Knowing the cause can help you avoid allergens, hives and swelling. Allergy tests include:
- Skin tests: During this test, healthcare providers test different allergens on your skin. If your skin turns red or swells, it means you’re allergic to that substance. This type of allergy test is also called a skin prick or scratch test. Skin testing is not commonly done if hives are chronic in nature.
- Blood tests: A blood test checks for specific antibodies in your blood. Your body makes antibodies to fight off allergens. The process is part of your immune system — but if your body makes too many, it can cause hives and swelling.