How many carbs are you eating, Dave? I'm not immobile but I can't do much in the way of exercise. I also have weight problems so I keep my carb intake pretty low (under 50g) most of the time - though I do occasionally have off days
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If Xyzzy is right about Metformin helping to prevent spikes (and I can see no reason why he shouldn't be), it might be worth considering taking it. Talk to your GP. You could ask to start on the slow release (SR) version to prevent digestive problems, and maybe just one a day to start with.
The other thing is, drink plenty of water. I try to get through 2 litres a day (which includes tea and coffee, but juices don't count!). I've heard on here that it helps flush the glucose out of your system.
If you do see a reading of 15 or over, phone NHS Direct and/or get yourself to A&E. Do you test your urine for ketones? Get yourself some test sticks. If you get high BGs and high ketones, A&E is your first port of call. Particularly if you feel nauseous as well.
It's unusual for Type 2s to get ketoacidosis, but we can.
Best of luck
Viv 8)