Diagnosis of allergies begins with a history and physical exam. The person may report symptoms after a specific exposure, such as being around cats.
Sometimes, the individual will have symptoms during particular seasons. For those with ongoing symptoms such as nasal stuffiness, other tests can be performed. The healthcare provider may order a test that looks for eosinophils in the nasal mucus. Allergy testing may be done to determine the particular triggers that cause the individual's symptoms.