The definitive way to discover if you have allergies and to get to the root cause of your hives is by having an allergy test. This test involves a trained medical professional exposing small segments of the skin to potential allergens and documenting the results. Once a list of allergens is determine, a list of certain triggers can be created, as it relates to food, medication and the environment.
Anytime you notice that you have an unexplained allergic reaction to something such as hives, it is best to go speak to a doctor. While the symptoms and reactions to an allergen very greatly and are commonly minute, it is important to note that they can be fatal.