If a spirometry test finds that a patient’s lung function is lower than the values that are considered normal for the patient’s age, height, ethnicity and sex, it may indicate the presence of chest or lung disease (e.g., asthma). Further testing may be recommended by the physician to confirm or rule out certain conditions. For example, to diagnose asthma a physician might suggest one or more of the following tests:

• Chest x-ray. Allows the physician to see some types of airway or lung damage.
  
  
• Allergy tests (e.g., skin test, RAST). A susceptibility to allergies can cause complications for someone with even a mild asthma condition. Allergy tests can detect sensitivity to certain allergens.
  
  
• Exercise challenge test. Most appropriate for individuals with a history of exercise-induced symptoms. The test is capable of detecting decreased lung function caused by exercise.
  
  
• Bronchoprovocation test. This test involves a patient being exposed to irritating substances and subsequent measurement of their lung function. It is not frequently used and should be conducted only in controlled labs by experienced physicians or specially trained personnel.

If the presence of asthma or another lung disease is confirmed, the physician will recommend appropriate treatments or medications. Treatments commonly associated with the treatment of asthma include:

• Bronchodilators (e.g., beta-agonists, anticholinergics). Medications that relax constricted muscles in the airways, allowing the user to breathe and cough up mucus more easily.
  
  
• Mast cell stabilizers (e.g., cromolyn, nedocromil). Medications that reduce inflammation in the airways, making it easier to breath and lowering the chance of a severe asthma attack.
  
  
• Corticosteroids. Medications that reduce the swelling in nasal passages during an asthmatic reaction, reducing or avoiding asthma symptoms. Though effective, these drugs can have many side effects.
  
  
• Leukotriene modifiers. Medications that prevent inflammation in the airways, halting the process that often leads to an asthma attack.

A new test to evaluate lung function has been approved by the U.S. Food and Drug Administration. The nitric oxide diagnostic test can successfully measure the amount of nitric oxide in the lungs. Patients with asthma and/or chronic bronchitis have increased levels of nitric oxide, although patients with COPD do not. This test can also indicate whether current asthma treatment is successful in a patient.