Examples of other common causes of dilated bronchi
| Other causes of dilated bronchi | How to differentiate from bronchiectasis |
| Normal ageing High altitude | Clinical context is key Bronchial dilatation tends to be generalised and mild (broncho–arterial ratio <1.5:1) No associated imaging findings of airway disease or inflammation |
| Regional hypoxia | Bronchial dilatation usually mild Bronchi may actually be normal in diameter but have increased broncho–arterial ratio due to small pulmonary artery secondary to hypoxic vasoconstriction |
| Bronchopneumonia | Acute clinical symptoms Comparison to prior studies May require re-imaging |