Hypoglycemia is a condition in which your blood sugar (glucose) level is lower than normal. Treatment involves quickly getting your blood sugar back to normal. If you think you have low blood sugar, please follow the steps given in our “Treating a Low Blood Sugar” chapter.

Reactive hypoglycemia is an acute reaction to a very high-carb food or meal. For instance, when there is a huge spike in blood sugar and compensating insulin secretion, the large insulin spike drives blood sugar very low several hours after the food/meal.


Mayo Clinic. “Hypoglycemia,” Mayo Clinic (March 13, 2020). https://www.mayoclinic.org/diseases-conditions/hypoglycemia/symptoms-causes/syc-20373685 (accessed on 8/2/2020).

Songster, Curtis Lee, MD, medical review. “Reactive Hypoglycemia,” Ketogenic Diet Resource (updated July 19, 2020). https://www.ketogenic-diet-resource.com/reactive-hypoglycemia.html

Treatment for Low Blood Sugar

You may feel shaky and think your sugar is low. If so, TEST.

A blood glucose over 70 mg/dL (3.9 mmol/l) is considered to be a “false low,” which feels low because you are used to having much higher blood glucose numbers! As you bring your numbers down, eventually numbers in the range of 70-99 mg/dL (3.8-5.6 mmol/l) will feel quite normal.

Anything under 67 mg/dL (3.8 mmol/l) is considered to be a true low blood sugar and should be treated in order to stay conscious. The best treatment for low blood sugar is pure glucose.

Dr. Bernstein says, “Glucose, the sugar of blood sugar, does not have to be digested or converted by the liver into anything else. Unlike other sweets, it’s absorbed into the blood directly through the mucous membranes of the mouth, stomach, and gut.” Table sugar is sucrose, a combination of glucose and fructose. Fruit is also a mixture of the sugars. Only glucose is, well, glucose!

Typically, one glucose tablet has 4 grams of sugar. Dr. Richard K. Bernstein, author of Dr. Bernstein’s Diabetes Solution: The Complete Guide to Achieving Normal Blood Sugars, says that 1 gram of pure glucose will raise your blood sugar about 5 mg/dL, so one tablet would raise your blood glucose by 20 mg/dL.

  1. If your meter shows you to have low blood sugar, take one glucose tablet (or one-half a tablet).
  2. Wait 20 minutes. Wash your hands and test your blood sugar again.
  3. Repeat until your blood sugar has returned to a normal range (70-99 mg/dL or 3.8-5.6 mmol/l).

That’s it! Correcting low blood sugar with glucose tablets is measurable and predictable.

If you still feel hungry after your meter shows that your blood sugar is normal, eat a protein/fat snack, such as 1 oz. cheese, 1/2 oz. raw almonds, or a hard-cooked egg. Do not eat anything with primarily carbohydrates.

*Note that your meter can be wrong. A meter can be up to 20% higher—or lower—than your blood level. So, a 70 mg/dL (3.9 mmol/l) could be 70 (3.9). Or, it could be between 56 and 84 mg/dl. How can you tell? Ask your doctor to order a fasting blood test. Bring your meter and test as close as you can to when your blood is drawn. Write down the result. When your blood tests come back, see how close it is to what the lab found. Then you know if your meter tends to be too high or too low.

Supporting Articles

Can you have hypoglycemia without diabetes?

Common Concerns about Low-Carb Dieting and Hypoglycemia

Common Mistakes on a Low Carb Diet

How Low-Carb Diets Can Affect Your Blood Sugar Levels

How to Cut Carbs When You Suffer From Hypoglycemia

Yes, a low-carb diet greatly lowers your insulin