A 'False Hypo' comes about because you may have been running high Bg levels for a while. Any drop in Bg levels can make your body think that you are dropping too low because it is used to higher levels.
Consequently you start to get the symptoms of a real hypo at a higher level.
Example. Normal higher Bg .........14 mmol/l.
Drop in Bg to say 8 mmol/l.
Body says .............too low !!!
Body gives out warning signals..., sweating, shaking, faintness, paleness, headache, tingling lips, blurred vision, irritability etc etc. All symptoms of a real below 4 mmol/l hypoglycaemia event.
But you are not that low, hence a 'false' hypo.
The problem gets worse if you treat it like a real hypo as you start eating Gluco tabs like there is no tomorrow if you haven't checked your meter reading. So then you go too high and start a 'roller coaster' effect ! So always check if you feel bad, never assume anything. Test !
The best way to try and get the numbers down in that event is to drink plenty of fluids, water, sugar free drinks etc, maybe even some exercise. Just don't eat anything and test after 20- 30 mins. You might still feel 'rubbish' though. The real cure is not to let Bg levels get that high in the first place.