Very low blood glucose (less than 20 mg/dL or 1.1 mmol/L).
What You Should Do
If you have symptoms such as weakness, sweating, nervousness, headache, or confusion, follow your doctor’s recommendation for treating hypoglycemia.
Conduct a control solution test using a new test strip. If the results of the control solution test are within the range printed on the side of your test strip vial, retest using blood and a new test strip.
If the retest using control solution does not work, or the error persists, call your local customer care office.