Unilateral renal artery stenosis causing hypertensive flash pulmonary oedema

Flash pulmonary oedema can occur as a result of multiple triggers that may act independently or in concert. One such precipitating factor is bilateral renal artery stenosis which can be treated either with revascularisation or with medical therapy. Unilateral renal artery stenosis, however, is a rare cause of flash pulmonary oedema, especially when the contralateral kidney is still functional. We describe a case of an elderly woman with a history of heart failure with preserved ejection fraction and multiple hospitalisations for hypertensive crisis and flash pulmonary oedema who was found to have right, ostial renal artery stenosis that was treated with stent placement.