The Dutch College of General Practitioners (NHG) guidelines 'Adult asthma' and 'COPD' have been revised. New spirometry reference values from the Global Lung Function Initiative are recommended. Airway obstruction is defined as a FEV1/FVC ratio below the 5th percentile for the reference population. Spirometry for diagnosis takes place without use of patients' inhaled medication and consists of measurements before and after standardized bronchodilation. In monitoring spirometry, patients continue using inhaled medication and standardized bronchodilation is not indicated. The goal of asthma management is optimal asthma control, tailored to individual goals. The most important non-drug intervention in asthma and COPD is to recommend stopping smoking. The goal of COPD management is to limit symptoms, improve exercise capacity and quality of life, and reduce the burden of disease. Inhaled corticosteroids are usually not indicated in COPD treatment. Patients with comorbid asthma and COPD are treated with non-drug interventions according to the COPD guideline and with medication according to the asthma guideline.