Tachycardia and low blood sugar

[keithlucas]

I am mildly diabetic and have recently started controlling my blood sugar through diet and excercise.
I monitor my blood sugar several times a day.
I seem to suffer tachycardia when my blood sugar falls below 5.5 or 100mg/dl.
My heart beat will race at 150 bpm and can stay there for hours. I feel no ill effects except mild trembling and shakiness. At the end of the episode, the rate can drop back to 80 bpm over a period of less than a minute.

I read that this should not be happenning until the sugar level is below 70 mg/dl.

Are some people less tolerant of low blood sugar than others?

[Veritas01]

I have precisely the same issue.  I have had a history of PVCs and AFIB as well as Tachycardia so I am familiar with the symptoms.  I am also a Type II Diabetic.  I take Metformin 1000 mg twice a day and Glyburide 5 mg in the AM and 2.5 in the PM.  Sometimes the Glyburide lowers my blood sugar too much particularly if I don't eat something a few hours after taking my meds.   As you mention my blood sugar will only be in the 80-90 range and I start to experience hypoglycemic symptoms.  Fatique, palpitations, sweating, shaking, feeling of dread...just a general awful feeling.  Mnay times I do have a racing heart and a rate of 120-160 BPM is common.  They are also very hard and forceful beats and a bit scary.  As soon as I take in some sugar (I have some glucose tablets but if they are not handy I drink a sugared soda or juice) I feel better in a few minutes though I sometimes have some fatigue and a headache after.   I know the conventional wisdom is that your blood sugar has to get down to 60 or below to be really hypoglycemic but that is not the case with me at all.  80 or below and I am off to the races.   I read in one article that some people can have an "adrenal" response to rapidly lowering blood sugar that mimics hypoglycemia and that may be it thought I can't find a lot about this.  So don't feel unique.  We are in the same boat.