Asthma Management Handbook

Considering alternative diagnoses in adults


Consider other possible causes of respiratory symptoms, including:

  • poor cardiopulmonary fitness
  • other respiratory conditions (e.g. bronchiectasis, chronic obstructive pulmonary disease, hyperventilation/dysfunctional breathing, inhaled foreign body, large airway stenosis, pleural effusion, pulmonary fibrosis, rhinitis/rhinosinusitis, upper airway dysfunction)
  • cardiovascular disease (e.g. chronic heart failure, pulmonary hypertension)
  • comorbid conditions (e.g. obesity, gastro-oesophageal reflux)
  • lung cancer.

Table. Findings that increase or decrease the probability of asthma in adults

Asthma is more likely to explain the symptoms if any of these apply

Asthma is less likely to explain the symptoms if any of these apply

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, medicines (e.g. aspirin or beta blockers), allergies, viral infections, laughter

Family history of asthma or allergies

Symptoms began in childhood

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 SABA bronchodilator

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

Symptoms only present during upper respiratory tract infections

Heavy smoker (now or in past)

Cardiovascular disease

Normal spirometry or PEF when symptomatic (despite repeated tests)

Adapted from:

Respiratory Expert Group, Therapeutic Guidelines Limited. Therapeutic Guidelines: Respiratory, Version 4. Therapeutic Guidelines Limited, Melbourne, 2009.

British Thoracic Society (BTS) Scottish Intercollegiate Guidelines Network (SIGN). British Guideline on the Management of Asthma. A national clinical guideline. BTS/SIGN, Edinburgh; 2012. Available from:

Asset ID: 2

How this recommendation was developed


Based on clinical experience and expert opinion (informed by evidence, where available).

Consider the possibility of upper airway dysfunction when FEV1/FVC ratio on spirometry is normal or when symptoms of breathlessness or wheeze do not improve after taking short acting beta2 agonist.

How this recommendation was developed


Based on clinical experience and expert opinion (informed by evidence, where available), with particular reference to the following source(s):

  • Benninger et al. 2011 1
  • Deckert and Deckert, 2010 2
  • Weinberger and Abu-Hasan, 2007 3
  • Morris and Christopher, 2010 4
  • Kenn and Balkissoon, 2011 5

Investigate cough thoroughly if there are findings that might indicate a serious alternative or comorbid diagnosis.

How this recommendation was developed


Based on clinical experience and expert opinion (informed by evidence, where available), with particular reference to the following source(s):

  • Gibson et al. 2010 6

If airflow limitation is not completely reversible, consider the possibility of COPD as an alternative diagnosis or a coexisting diagnosis (including asthma-COPD overlap), especially in smokers and ex-smokers over 35 years old and in people over 65 years old.

How this recommendation was developed


Based on clinical experience and expert opinion (informed by evidence, where available), with particular reference to the following source(s):

  • Abramson et al. 2012 7

Consider the possibility of adult-onset asthma in people with dyspnoea, wheeze or cough, even if they have no previous diagnosis of asthma.

How this recommendation was developed


Based on clinical experience and expert opinion (informed by evidence, where available).

More information

Upper airway dysfunction

Upper airway dysfunction is intermittent, abnormal adduction of the vocal cords during respiration, resulting in variable upper airway obstruction. It often mimics asthma12 and is commonly misdiagnosed as asthma.34 It can cause severe acute episodes of dyspnoea that occur either unpredictably or due to exercise.3 Inspiratory stridor associated with vocal cord dysfunction is often described as ‘wheezing’,3 but symptoms do not respond to asthma treatment.25

Upper airway dysfunction can coexist with asthma.1 People with asthma who also have upper airway dysfunction experience more symptoms than those with asthma alone and this can result in over-treatment if vocal cord dysfunction is not identified and managed appropriately.1

Upper airway dysfunction probably has multiple causes.1 In some people it is probably due to hyperresponsiveness of the larynx in response to intrinsic and extrinsic triggers.18 Triggers can include exercise, psychological conditions, airborne irritants, rhinosinusitis, gastro-esophageal reflux disease, and medicines.24

Upper airway dysfunction should be considered when spirometry shows normal FEV1/FVC ratio in a patient with suspected asthma4 or symptoms do not respond to short-acting beta2 agonist reliever. The shape of the maximal respiratory flow loop obtained by spirometry may suggest the diagnosis.3 Direct observation of the vocal cords is the best method to confirm the diagnosis of upper airway dysfunction.1

Is it asthma, COPD or both?

The main symptoms of chronic obstructive pulmonary disease (COPD) are breathlessness, cough and sputum production. Chest tightness, wheezing and airway irritability are also common. Patients often attribute breathlessness to ageing or poor cardiopulmonary fitness.7

The definitions of asthma and COPD overlap, and asthma and COPD frequently coexist in people aged 65 years and over.9 Comorbid COPD is often misdiagnosed as asthma in older people,9  and vice versa.

For information on diagnosis and management of COPD, refer to the COPD-X Concise Guide for Primary Care.10

The Global Initiative for Asthma (GINA) and Global Initiative Obstructive Lung Disease (GOLD) recommend the following stepwise approach for adults presenting with respiratory symptoms:11

  1. Identify whether the patient has clinical features of, or is at risk of, chronic airway disease. This may be suggested by the clinical history and physical examination.
  2. Identify features that favour a diagnosis of typical asthma or typical COPD. If several features of both are present, asthma-COPD overlap is likely.
  3. Perform spirometry to confirm airflow limitation.
  4. Start treatment, selected according to whether the assessment favoured the single diagnosis of asthma, the single diagnosis of COPD, or asthma-COPD overlap.
  5. Refer for specialist assessment and other investigations, if necessary.


Cough and asthma in adults

When no other asthma symptoms are present, chronic cough (present for more than 8 weeks) is unlikely to indicate asthma.

Chronic cough may be due to asthma if:6

  • cough is episodic
  • cough with exercise is associated with other symptoms that suggest airflow limitation (expiratory wheeze or breathlessness)
  • spirometry confirms reversible airflow limitation.

If cough is due to asthma, it should respond to treatment with an inhaled corticosteroid preventer taken regularly and reliever as needed).6

Findings that suggest a serious alternative or comorbid diagnosis that requires further investigation include:6

  • haemoptysis
  • smoker with > 20 pack–year smoking history
  • smoker aged over 45 years with a new cough, altered cough, or cough with voice disturbance
  • prominent dyspnoea, especially at rest or at night
  • substantial sputum production
  • hoarseness
  • fever
  • weight loss
  • complicated gastro-oesophageal reflux disease
  • swallowing disorders with choking or vomiting
  • recurrent pneumonia
  • abnormal clinical respiratory examination.
Spirometry in diagnosis and monitoring

Spirometry is the best lung function test for diagnosing asthma and for measuring lung function when assessing asthma control. Spirometry can:

  • detect airflow limitation
  • measure the degree of airflow limitation compared with predicted normal airflow (or with personal best)
  • demonstrate whether airflow limitation is reversible.

It should be performed by well-trained operators with well-maintained and calibrated equipment.12, 13

Before performing spirometry, check if the person has any contraindications (e.g. myocardial infarction, angina, aneurysm, recent surgery, suspected pulmonary embolism, suspected pneumothorax, fractured ribs). Advise them to stop if they become dizzy.

Clearly explain and physically demonstrate correct spirometry technique: 14

  • Sit upright with legs uncrossed and feet flat on the floor and do not lean forward.
  • Breathe in rapidly until lungs feel absolutely full. (Coaching is essential to do this properly.)
  • Do not pause for more than 1 second.
  • Place mouthpiece in mouth and close lips to form a tight seal.
  • Blast air out as hard and fast as possible and for as long as possible, until the lungs are completely empty or you are unable to blow out any longer.
  • Remove mouthpiece.

Repeat the test until you obtain three acceptable tests and these meet repeatability criteria.

Acceptability of test

A test is acceptable if all the following apply:

  • forced expiration started immediately after full inspiration
  • expiration started rapidly
  • maximal expiratory effort was maintained throughout the test, with no stops
  • the patient did not cough during the test
  • the patient did not stop early (before 6 seconds for adults and children over 10 years, or before 3 seconds for children under 10 years).

Record the highest FEV1 and FVC result from the three acceptable tests, even if they come from separate blows.14

Repeatability criteria

Repeatability criteria for a set of acceptable tests are met if both of the following apply:12

  • the difference between the highest and second-highest values for FEV1 is less than 150 mL
  • the difference between the highest and second-highest values for FVC is less than 150 mL.

For most people, it is not practical to make more than eight attempts to meet acceptability and repeatability criteria.14

Testing bronchodilator response (reversibility of airflow limitation)

Repeat spirometry 10-15 minutes after giving 4 separate puffs of salbutamol (100 mcg/actuation) via a pressurised metered-dose inhaler and spacer.14 (For patients who have reported unacceptable side-effects with 400 mcg, 2 puffs can be used.)

For adults and adolescents, record a clinically important bronchodilator response if FEV1 increases by ≥ 200 mL and ≥ 12%.14

For children, record a clinically important bronchodilator response if FEV1 increases by
≥ 12%.14



  1. Benninger C, Parsons JP, Mastronarde JG. Vocal cord dysfunction and asthma. Curr Opin Pulm Med. 2011; 17: 45-49. Available from:
  2. Deckert J, Deckert L. Vocal cord dysfunction. Am Fam Physician. 2010; 81: 156-159. Available from:
  3. Weinberger M, Abu-Hasan M. Pseudo-asthma: when cough, wheezing, and dyspnea are not asthma. Pediatrics. 2007; 120: 855-864. Available from:
  4. Morris MJ, Christopher KL. Diagnostic criteria for the classification of vocal cord dysfunction. Chest. 2010; 138: 1213-23. Available from:
  5. Kenn K, Balkissoon R. Vocal cord dysfunction: what do we know?. Eur Respir J. 2011; 37: 194-200. Available from:
  6. Gibson PG, Chang AB, Glasgow NJ, et al. CICADA: cough in children and adults: diagnosis and assessment. Australian cough guidelines summary statement. Med J Aust. 2010; 192: 265-271. Available from:
  7. Abramson MJ, Crockett AJ, Dabscheck E, et al. The COPD-X Plan: Australian and New Zealand guidelines for the management of chronic obstructive pulmonary disease. Version 2.34. The Australian Lung Foundation and The Thoracic Society of Australia and New Zealand, 2012. Available from:
  8. Gimenez LM, Zafra H. Vocal cord dysfunction: an update. Ann Allergy Asthma Immunol. 2011; 106: 267-274. Available from:
  9. Gibson PG, McDonald VM, Marks GB. Asthma in older adults. Lancet. 2010; 376: 803-813. Available from:
  10. Abramson M, Frith P, Yang I, et al. COPD-X Concise Guide for Primary Care. Lung Foundation Australia, Brisbane, 2016. Available from:
  11. Global Initiative for Asthma (GINA). Global strategy for asthma management and prevention. GINA, 2016. Available from:
  12. Miller MR, Hankinson J, Brusasco V, et al. Standardisation of spirometry. Eur Respir J. 2005; 26: 319-338. Available from:
  13. Levy ML, Quanjer PH, Booker R, et al. Diagnostic Spirometry in Primary Care: Proposed standards for general practice compliant with American Thoracic Society and European Respiratory Society recommendations. Prim Care Respir J. 2009; 18: 130-147. Available from:
  14. Johns DP, Pierce R. Pocket guide to spirometry. 3rd edn. McGraw Hill, North Ryde, 2011.