We describe a patient with multiple symptoms but whose primary complaint was of headache, in whom no firm diagnosis was made in two years, who was resistant to all treatment, until a markedly asymmetrical cranial venous outflow came to be regarded, not as normal variant anatomy but as fundamental to the clinical problem. Deliberately altering this anatomy in favour of a more symmetrical arrangement by stenting a hypoplastic transverse sinus brought about an immediate, profound and sustained clinical improvement. This result challenges the existing consensus on what is acceptable as normal in respect of cranial venous outflow. It raises intriguing questions about the relationship between neurological symptoms and the vagaries of cranial venous outflow anatomy. It suggests there may be new opportunities in the investigation of chronic headache.