hi Marti.... having had a lot of hypos myself, I get bad brain fog afterwards... so I would think a headache is possible from the hypo for some. I tend to get headaches if my BGL is too high. But a hypo itself is actually draining your brain of glucose which it needs for energy so maybe your body's reaction to that is a headache? We're all different really. Sometimes I am nauseated after a hypo too... it probably just depends on so many factors happening at the time. I hope the clinic can help to resolve it for you.