Table 3. Common initial diagnostic investigations for chronic dyspnoea.

Investigation	Possible diagnoses
Blood tests	Anaemia, metabolic acidosis, renal or liver disease, thyroid disease, congestive cardiac failure
Chest X-ray	COPD, interstitial lung disease, pleural effusion, pulmonary malignancy, congestive cardiac failure
Electrocardiogram	Arrhythmias, ischaemic heart disease, congestive cardiac failure
Spirometry	COPD, asthma, restrictive lung diseases

COPD, chronic obstructive pulmonary disease.