An 82-year-old male presented with a week's history of shortness of breath on exertion, particularly when bending to tie his shoe laces. The breathlessness worsened on standing and was relieved by lying. His oxygen saturations were noted to fluctuate based on position dropping to 82% on standing. This was suggestive of platypnoea-orthodeoxia syndrome (POS), an uncommon but potentially reversible diagnosis. As the population ages we may be more likely to see patients with persisting patent foramen ovale decompensate and develop POS.