How can this happen?

[TuTusweet]

I've been doing well with my low carb diet. My morning BG is consistently about 6.3. Before it was 7.6.
Yesterday was a normal food day--Cheese and sliced salami lunch and dinner green beans and broccoli with fish baked in a bag with butter melted in the fish juices to make sauce. Where are the carbs in that ?
During the night I had bad cramp in my left leg with a feeling it was cold and slightly numb.* This morning up late--felt rotten--shakey tired cold bit dizzy. Tested at midday after a thin biscuit and two cups of tea with sweetener and the reading was 8.3.
Puzzling and worrying.
I though shakiness and dizzyness was a sign of low BG not high. How could it be so high after a very low carb day?
I'm running out of ideas and confidence now.
Comments welcome please.
* There is a long history of problems with my left leg so I think any symptoms will be confusing.

 

[mo1905]

A one-off slightly higher than normal reading is nothing to worry about. The meters have approx 20% tolerance in them so you could have actually been 4.7 ! Yes, your meal was extremely low carb but even protein can cause a BG rise. As for your shakiness and dizzy feeling, I'm not sure. Perhaps it could be non diabetes related ? If your morning readings become continually higher than you'd like, then it's worth investigating.

 

[douglas99]

6.7, not 4.7, for 20%.
But that could be anything. A one off reading could even be something on your finger off the biscuit or sweetener.