Features suggesting higher or lower probability of asthma in adults and adolescents

Asthma is more likely to explain signs/symptoms

More than one of these symptoms: wheeze, breathlessness, chest tightness, cough

Symptoms recurrent or seasonal

Symptoms worse at night or in the early morning

History of allergies (e.g. allergic rhinitis, atopic dermatitis)

Symptoms obviously triggered by exercise, cold air, irritants, certain medicines (e.g. aspirin or beta blockers), allergies, viral infections

Family history of asthma or allergies

Widespread wheeze audible on chest auscultation

FEV1 or PEF lower than predicted, without other explanation

Eosinophilia or raised blood IgE level, without other explanation

Symptoms rapidly relieved by a rapid-acting bronchodilator (e.g. SABA or ICS-formoterol)

Asthma is less likely to explain the signs/symptoms

Dizziness, light-headedness, peripheral tingling

Isolated cough with no other respiratory symptoms

Chronic sputum production

No abnormalities on physical examination of chest when symptomatic (over several visits)

Change in voice

Heavy smoker (now or in past)

Cardiovascular disease

Normal spirometry when symptomatic (despite repeated tests)

Additional information

FEV1: forced expiratory volume in 1 second; ICS: inhaled corticosteroids; PEF: peak expiratory flow; Ig: immunoglobin; SABA: short-acting beta2 agonist