Table 1– Diagnostic approach in vocal cord dysfunction

Evaluation/test	Typical findings
History (nonspecific)	Throat tightness/closure, globus sensation, chest tightness, audible wheezing (inspiratory versus expiratory), stridor triggers: irritants, exercise trigger poor response or aggravation by inhaled medications (MDI>nebulised)
Lung function tests
Symptom-free period	Normal findings?
	MIF₅₀<MEF₅₀?
Acute dyspnoea (may be provoked by methacholine/ histamine challenge, exercise, irritant challenge)	Inspiratory or expiratory flow limitationTruncated flow-volume loopsDeviation of the resistance loop (inspiratory/expiratory)?Laryngoscopy (endospirometry)
ENT examination (laryngoscopy)	Post-nasal drip?
	LPR?
Evaluation of reflux GER disease/LPR	pH probe

ENT: ear, nose and throat; GER: gastro-oesophageal reflux; LPR: laryngopharyngeal reflux; MDI: metered dose inhaler; MIF₅₀: maximal inspiratory flow at 50% of forced vital capacity; MEF₅₀: maximal expiratoy flow at 50% of forced vital capacity.