How to determine if i really have asthma?

Testing: A lot of different medical problems have similar symptoms to asthma. The best way to confirm the diagnosis is with a methacholine challenge test - a special type of pulmonary function test. Your breathing is tested while a therapist gives you an inhaled medication called methacholine. In patients with asthma, this will cause the airways to spasm at low doses - a "positive" test.

See a Doc: Asthma is a clinical diagnosis. There is no set test that will tell one that they have asthma or not. One's doc will take a history, perform an exam and order some tests. Once these are all done then they should be able to determine if one has asthma or not.