Trigger tests. If your other results are normal, but you’ve been experiencing signs and symptoms of asthma, your doctor may use known asthma triggers to try and provoke a mild reaction. If you don’t have asthma, you won’t react. But if you do have asthma, you likely will develop asthma symptoms.
http://www.aafa.org/page/asthma-diagnosis.aspx
1 This test detects decreased lung function caused by exercise. 2  Your doctor may take a chest x-ray (radiograph) if the asthma isn't helped by the usual treatments.  Allergy testing can be used to identify factors your child is allergic to because these factors might contribute to asthma.
http://www.emedicinehealth.com/asthma_in_children/page6_em.htm
1 Examine your nose, throat and upper airways. 2  Use a stethoscope to listen to your breathing. Wheezing — high-pitched whistling sounds when you breathe out — is one of the main signs of asthma.  Examine your skin for signs of allergic conditions such as eczema and hives.
http://www.mayoclinic.org/diseases-conditions/asthma/in-depth/asthma/ART-20045198
Asthma: Steps in testing and diagnosis. Diagnosing asthma generally includes a medical history, physical exam and lung tests. By Mayo Clinic Staff. Asthma diagnosis is based on several factors, including a detailed medical history, a physical exam, your symptoms, and overall health and test results.
http://www.mayoclinic.org/diseases-conditions/asthma/in-depth/asthma/ART-20045198
Asthma: Steps in testing and diagnosis. Diagnosing asthma generally includes a medical history, physical exam and lung tests. Asthma diagnosis is based on several factors, including a detailed medical history, a physical exam, your symptoms, and overall health and test results.
http://www.mayoclinic.org/diseases-conditions/asthma/in-depth/asthma/ART-20045198
To diagnose asthma, your doctor will discuss your medical history with you and perform a physical exam. You may need a lung function test and maybe other tests, such as a chest or sinus X-ray. If you or your child are having problems breathing on a regular basis, don’t wait! Visit a doctor immediately.
http://www.aafa.org/page/asthma-diagnosis.aspx
1 Some lung treatment centers use cold air to attempt to provoke an asthma response.  Patients with a history of exercise-induced symptoms (eg, cough, wheeze, chest tightness, pain) can undergo an exercise challenge test. This test is usually done in children older than 6 years. The baseline (or usual) lung function for the child is measured (using spirometry) while the child is sitting still.
http://www.emedicinehealth.com/asthma_in_children/page6_em.htm
Tests Used to Diagnose Asthma. Pulmonary function tests (PFTs) are used to test lung performance, but in children younger than 5 years, the results are typically not reliable.
http://www.emedicinehealth.com/asthma_in_children/page6_em.htm
To learn about your lung health, your doctor may want you to have several pulmonary function tests done including spirometry, lung volumes, diffusing capacity, and airway resistance. Most of these breathing tests are done by blowing into a tube while sitting in a chair.
http://getasthmahelp.org/pft.aspx
Your doctor may: 1  Examine your nose, throat and upper airways. 2  Use a stethoscope to listen to your breathing. Wheezing — high-pitched whistling sounds when you breathe out — is one of the main signs of asthma.  Examine your skin for signs of allergic conditions such as eczema and hives.
http://www.mayoclinic.org/diseases-conditions/asthma/in-depth/asthma/ART-20045198
what test is used to diagnose asthma
Lung tests are used to diagnose asthma. Lung test is used to diagnose asthma .  Lung tests is used to diagnose asthma.   Lung test is used to diagnose asthma.