From your comment:
"...this process basically requires two things at the same time -- very high blood sugar levels and very high blood ketone levels. If you only have one or the other, there's little danger."

Thank you for this. I registered 10 on my Ketoscan the other night and while I felt fine, I was a little surprised that I would get that high and wondered where that put me in the ketosis range. I have never been diagnosed as diabetic but I have felt I may have been. Still, I'm sure my bg is no higher than 110, what with my carb level.

10 what? Is it 10 mmol/ml? If so, that IS getting awfully high. If you ARE diabetic, then its possible to have high blood sugars even without much (or any) carb intake. Are you unusually thirsty and drinking lots of water? That's a strong indication of uncontrolled diabetes (though there are other causes, too).

So I just went and did some checking and a Ketoscan is a breath analyzer that measures acetone in ppm (parts per million), not ketones. The information I've found indicates that 10 ppm acetone is a fairly mild level of ketosis. People following ketogenic diets are typically above 40 ppm and as high as 200 ppm after prolonged fasts. The range that is reached by people in ketoacidosis is more like 1200 ppm or more. So you should be fine.

If you have wondered whether you are diabetic, then it would be a good idea to go ahead and get your HbAc1 checked. You can get home test kits for about $20 that are just about as accurate as the full-up lab tests. You can be diabetic for years without knowing it, so it's good peace-of-mind if it comes in normal and, if not, you can save yourself years of accumulated damage by knowing now instead of later.

Another thing I noted was that breath ketones, which correlate well with breath acetone, is not a good indicator of blood ketones, which is what really matters from the standpoint of ketoacidosis. But the ranges are so disparate that if one is really, really high, the other is likely really, really high as well.

Oh, it's PPM. I didn't know that was a thing for ketones. I thought it was always mmol/ml. I am not particularly thirsty. I have to remind myself to drink.

It's not measuring ketones at all. It is measuring acetone in your breath in parts per million. There's no good way to correlate acetone in your breath to the amount of ketones in your blood. If one is low, the other is not likely to be very high and vice-versa, but that's about as far as it goes.

Thank you for the information. I knew it measured acetone, but I also found a lot of people who compared it to their blood meters and found a pretty fair correlation. I didn't think about the difference in the measurements. I'm fine with the range of ketosis it indicates. All the lc mds I heard from - Phinney for instance - say it's good.
I just would not be able to buy enough strips to use it the way I use the breath meter.
So, again, thanks.

I was diabetic without feeling thirsty for years, and now that my blood glucose is pretty well controlled, have thirst only at night, but possibly associated with dry mouth from thyroid issues. I'd recommend getting a home kit and checking yourself. Anyone who is over 30 and overweight should do this IMHO.