Wheezing
Cough
Accessory muscle use
Dyspnea
Prolonged expiration
Severity of retractions occurs in caudal to cephalad direction
Scalene muscle contractions more severe than subcostal and intercostal retractions
Sign of impending ventilatory failure
Paradoxical respiration
Chest deflation and abdominal protrusion during inspiration
Altered mental status
"Silent chest"
Scalene muscle contractions more severe than subcostal and intercostal retractions
Paradoxical respiration
Chest deflation and abdominal protrusion during inspiration
Altered mental status
"Silent chest"
Chest deflation and abdominal protrusion during inspiration
Acute asthma exacerbation 
Upper Airway diseases
COPD exacerbation
Allergic rhinitis and sinusitis
Acute chest syndrome
Large Airway Obstruction
Acute dyspnea
Foreign body aspiration