Review symptoms: chronic cough, sputum production, shortness of breath, wheezing
Assess risk factors: smoking history, biomass exposure, occupational dust or chemicals, air pollution, family history
Perform physical examination: breath sounds, prolonged expiration, use of accessory muscles, signs of hyperinflation
Order spirometry before and after bronchodilator
Confirm COPD if post-bronchodilator FEV1/FVC is less than 0.70
Measure severity with FEV1 percent predicted
Consider chest X-ray to rule out other causes
Consider CT scan if diagnosis is unclear or to assess emphysema or other lung disease
Check oxygen saturation with pulse oximetry
Obtain arterial blood gas if severe disease or low oxygen levels are suspected
Evaluate for alpha-1 antitrypsin deficiency in younger patients or those with minimal smoking history
Rule out asthma, heart failure, bronchiectasis, tuberculosis, and interstitial lung disease
Assess exacerbation history and symptom burden using validated tools such as CAT or mMRC