• Acute partial obstruction
• Respiratory distress – dyspnoea, tachypnoea, short sentences, agitation, diaphoresis
• Coughing, choking, gagging and altered voice
• Grunting and snoring – partial obstruction of pharynx by soft palate or epiglottis
• Stridor
• Drooling and gurgling
• Paradoxical chest wall movements and supraclavicular retraction
• Dermal ecchymoses and subcutaneous emphysema – if very forceful respiratory effort
• Negative pressure pulmonary oedema – may be misdiagnosed as acute heart failure
• Rapid decompensation and progression to complete obstruction

Subacute or chronic partial obstruction

• May be almost asymptomatic at rest if develops gradually
• Dyspnoea and tachypnoea
• Stridor
• Voice change
• Hypercapnic ventilatory failure
• Sudden progression to complete obstruction

Complete obstruction

• Inability to breathe and speak
• May clasp throat between thumb and index finger to indicate choking
• Agitation and panic
• Cyanosis
• Vigorous respiratory effort becoming feeble as consciousness lost
• Respiratory arrest, bradycardia and hypotension followed swiftly by cardiac arrest if not relieved