What does it mean when a Glucometer says Hi (High)?

Dr. Datta Reddy Aakiti
MBBS, MD, DM (Endocrinology)

Blood glucose monitoring with glucometer and adjustment of the treatment, especially insulin, is one of the effective treatment strategies in the management of the Diabetes Mellitus.

The reported result range of most of the available glucometers are 20–600 mg/dL.

If the blood glucose values are within this range, the glucometer displays the values.

If the blood glucose is out of this range, then the glucometer doesn’t show the value. Instead, it displays HI or LO.

The two readings which require an immediate response are HI and LO.

If your glucometer displays HI, it means you may have a very high blood glucose level (severe hyperglycemia) exceeding 600 mg/dl.

high hi glucometer reading

  • Immediately re-check your glucose level. If the result is HI again, this may indicate a severe problem with your blood glucose control.
  • Consult your doctor as soon as possible for the proper management of your diabetes mellitus.
  • You may need to take more insulin, which will help to reduce the blood glucose levels.
  • If possible, check your urine for ketones, which is very much vital, especially if you are a Type 1 DM patient. If the urine ketones are positive, immediately consult the doctor.
  • Take more fluids to prevent the development of Diabetic Keto Acidosis (DKA) (one of the common preventable complications of uncontrolled Diabetes).
  • Follow the doctor’s advice for the better control of your blood glucose to prevent long term complications of uncontrolled Diabetes.

If your glucometer shows LO, it means your blood glucose levels very low (severe hypoglycemia) lower than 20 mg/dl.

  • It is an emergency like situation, immediately drink glucose water or eat sugar candy or glucose tablet and eat some biscuits or some food to prevent further hypoglycemia.