Table 2.

Characteristics that support a diagnosis of asthma or COPD, grouped by category

	Characteristics favoring diagnosis of asthma	Characteristics favoring diagnosis of COPD
Age	Onset <2 0 years	Onset > 40 years
Respiratory symptoms	Variation of symptoms with time	Symptoms persist regardless of treatment
	Worsening of symptoms at night or in morning	Usually have daily symptoms and dyspnea with good and bad days
	Triggers for symptoms noted including exercise, emotion, dust or allergen exposure	Chronic bronchitis symptoms precede onset of dyspnea and not necessarily related to triggers
Lung function	Variability in airflow obstruction using peak flows or spirometry	Airflow obstruction often persistent or fixed
Lung function between symptoms	Lung function normal between symptoms	Lung function abnormal between symptoms
History	Previously diagnosed by doctor with asthma	Previously diagnosed by doctor with COPD, emphysema, chronic bronchitis
	Family history of asthma, allergic disease	Heavy exposure history common: tobacco smoke, biomass fuels
Time course	Symptoms do not worsen over time, but vary seasonally or from year to year	Symptoms progress slowly over time
	Can improve quickly and respond quickly to therapies such as ICS or bronchodilators	Symptoms often have limited response to short acting inhalers
Imaging	Chest Xray usually normal	Chest Xray reveals severe hyperinflation
The GINA/GOLD statement notes that if three or more characteristics are present for one either asthma or COPD, it is suggested that the patient likely has that disease, however if there are a similar number of boxes checked for both, then a diagnosis of ACOS is considered.

Adapted from GOLD Ga. Diagnosis of Diseases of Chronic Airflow Limitation: Asthma, COPD, and Asthma-COPD Overlap Syndrome (ACOS); 2015; with permission.