Asthma is a chronic (ongoing) inflammation of the airways that affects the breathing patterns of millions of people. The disease is highly treatable, but difficult to diagnose because no single test detects it. In addition, many other lung diseases share symptoms with asthma, further complicating diagnosis.

There are several diseases that mimic asthma and thus complicate a physician’s ability to make an accurate diagnosis. This is especially true in adults. Chronic obstructive pulmonary disease (COPD), a disease usually caused by years of smoking, sometimes has symptoms that make it very difficult to distinguish from asthma. Other disorders, such as bronchitis and cardiac asthma, also can be misdiagnosed as asthma.

The task of correctly diagnosing children is usually a bit easier. Diseases that mimic asthma in children – such as cystic fibrosis (a glandular disorder that affects the lungs) and bronchiectasis (damage to the bronchial tubes) – often can be confirmed through testing. A pattern of episodic coughing (with or without wheezing) usually indicates asthma. However, there are disorders in children that can be misdiagnosed as asthma, including congenital (present at birth) heart disease, bronchopulmonary dysplasia (a chronic lung disease), primary immunodeficiency (disease that triggers autoimmune disease or unusual susceptibility to infection) and upper airway disease.

A proper diagnosis is important, because it gives physicians a roadmap for treating the patient most effectively.