Subdural haematomas can result from bridging vein rupture. Rotational acceleration in the sagittal plane and in a forward direction, as in falls, is very likely the 'mechanical' cause of subdural haematoma, as shown in cadaveric studies. Some recreational activities, for example roller-coaster rides and bungee jumping, have been associated with subdural haematoma, owing to acceleration/deceleration or repetitive head movements. We report a case of chronic subdural haemorrhage in a male teenager without precipitating factors and no history of head trauma. This case shows the value of good history-taking in medical diagnosis and that one should be aware of the risks of violent sports or dancing and the minimal clinical signs encountered.