Asthma Diagnosis

Asthma is a common chronic disease of the airways in the lungs. The symptoms of asthma include shortness of breath, wheezing, coughing, and tightness of chest. There is no single test to diagnose asthma, but the doctor can decide if a person has asthma based on the information given by him or her. Doctors are able to diagnose asthma by going through the case history of a person and at times to confirm if a person is an asthmatic or no, few breathing tests may be recommended.

Few Methods For Diagnosis Of Asthma:

• The doctor will try and understand the health condition after the patient gives his/her medical history and informs about the symptoms he or she is experiencing. The doctor will examine the person, and perform some breathing tests.
• It is important for a person to share, accurate information about symptoms, medication, allergies, and other health related problems he or she is experiencing or has experienced in the past. The doctor may recommend tests needed to be done or prescribe the appropriate medication, based on the type of asthma diagnosed and the pattern of symptoms observed.  
• It is important to be aware of the family’s medical history, and knowing if anyone had asthma or allergy. This will help the doctor to look in a little deeper into a patient’s complaints and determine whether he or she needs to be tested for asthma.

These are some main tests that can help diagnose asthma:

• Spirometry is a simple and widely available tool for testing the lung’s function. A person blows into a machine that measures how fast he can breathe out and how much air he can hold in his lungs. This test helps to know the air holding capacity of the lungs, and how well is a person’s breathing function. Such measurements characterize the patient, identify heterogeneity and allow treatment to be personalized. This is one of the most reliable ways to diagnosing asthma and it can be used to test other lung diseases as well. It takes approximately 10 minutes for the test and sometimes it is repeated after taking the puffer medications. For someone who is already diagnosed with asthma, spirometry can be useful to determine if the current treatment is working.
• FeNo or an exhaled nitric oxide testis a test wherein a person has to breathe into a machine, which measures the level of nitric oxide in the breath. Nitric oxide is a gas produced by the cells involved in the inflammation of airways. FeNo test is performed using a portable device and it is different from other lung function tests. This test helps to know if there is inflammation associated with allergic asthma and also the severity of inflammation caused. It will help the allergist to know if the treatment is helping to suppress the nitric oxide level.
• Peak Flow Test is done using a handheld device, and it measures the ability of a person to push air out of the lungs. This test may be done several times to see if results change over time. Also, there are two ranges to measure the air pushed, and the low range peak flow meter is used to test children. The higher range meter is used for adults as they have larger airways than children. Several types of peak flow meters are available and one must consult with the doctor to know which should be used by them.
• Impulse Oscillometry (IOS) provides a rapid, measure of airway impedance.  For this test the patient needs to perform simple tidal breathing manoeuvres that require less effort and co-operation than spirometry. It can be used in the diagnosis and management of diseases of the airways in children. Also, this test has much higher sensitivity to detect airways obstruction.

Diagnosis for Children

Asthma is the commonest chronic disease in children. An early asthma diagnosis is important for the proper treatment of young children with respiratory symptoms. It might not be possible to diagnose children with conventional tools. In children younger than 5 years of age it is often difficult to differentiate between viral induced wheezing and asthma. Spirometry and peak flow test can help in confirming the diagnosis of asthma in children above 5 years of age. Oscillometry test can also be used in the diagnosis and management of diseases of the airways in children.