Your doctor will need to ask many questions in an attempt to find the possible cause of hives or angiodema. Since there are no specific tests for hives -- or the associated swelling of angioedema -- testing will depend on your medical history and a thorough exam by your primary care doctor or dermatologist.
Skin tests may be performed to determine the substance to which you are allergic. Routine blood tests are done to determine if a system-wide illness is present.