Low Blood Sugars (Hypoglycemia)

A low blood sugar, also called hypoglycemia or an insulin reaction, is defined as a blood glucose level below 60 to 70 mg/dl. People on insulin are often concerned that excess insulin may drive their blood sugar too low. Mild lows can be annoying or embarrassing, while severe lows can be dangerous.

Frequent or severe low blood sugars mean that too much insulin is being given for a person’s current weight, activity level, and carb intake. This is especially true if lows occur within one to three hours after a carb bolus or when more than 20 grams of glucose is required to bring the blood sugar back to normal. At the first sign that lows are becoming frequent, call your physician/health care team to discuss lowering your basal and bolus doses by 5% to 10%.

A low blood sugar may cause you to shake, sweat, and feel disoriented, or impair your mental awareness and reaction times. Thinking becomes impaired because glucose supplies, which the brain relies on to function, are unavailable and, unlike other organs, the brain cannot switch to alternative fuels to operate. loss of coordination, confusion, the release of stress hormones, and irritability usually begin when the blood sugar goes below 60 mg/dl (3.3 mmol).

You may misjudge your condition and begin to argue with others who notice the distinct change in your personality and performance. Confusion and irritability during hypoglycemia often cause a person to deny they are having a problem, and may severely challenge the efforts of others who are trying to help.

Having one insulin reaction increases the risk for another. In one study, 46% of the people who had a reaction had another reaction the same day and another 24% had a reaction on the second day.  Unfortunately, the second reaction is harder to recognize because stress hormones, which create symptoms like sweating and shaking, are largely depleted by the first reaction for the next 2 to 3 days! See Hypoglycemia Unawareness for more information.

Be sure to consult with your physician or the health care team if you are uncertain what to do to stop low blood sugars, or you are gaining unwanted weight because carb intake is the only tool to remedy hypoglycemia. Remember or write down solutions they suggest so you can be on top of things when this or similar situations reappear. With experience, you will be able to make your own insulin dose adjustments.


Diabetes Response Service – the only scheduled proactive self-management Personal Call System using live operators to monitor, alert and prevent severe diabetic hypoglycemia.