So I assume is the CAA AME at Gatwick . I am sure he is an expert ,but when I say what I have said and it is downtrodden as if I am some sort of liar then that is not appreciated. In the PPL and atpl syllabus it clearly states that the effects of hypoxia can begin at 8000 ft . Mine began between 8500 and 9000 , consistent with the gen given by the syllabus and that given in the baro chamber in the RAF. I recently passed a class one so my health is deemed to be good . I have also recently had so many tests you wouldnt believe due to a suspected kidney issue . I am as healthy as can be , gym 4 times a week and rugby on a saturday . I just happen to show symptoms of hypoxia early . If based on the above info anyone wants to tell me what I am suffering from then by all means do so , But half the doctors in gatwick / cheshire manchester think Im A1 so surely that should be enough for people not to deride my comments when I am detailing an experience I have had . Experts they may be bit in this case I am afraid they are very wrong . Based on my personal experiences