Asthma can be hard to diagnose; therefore, its symptoms are sometimes misdiagnosed as respiratory infections or attributed to other conditions. Generally, with a thorough medical evaluation, which includes a physical, a medical history that includes evaluating your symptoms, different laboratory tests and respiratory-function tests, a diagnosis is quickly and accurately made. Once diagnosed, it can take some time for your health care team to determine which medications and dosages are right to best manage your symptoms.