Confusen - my blood sugar numbers are in the 90 to 130 range.

Answer by Dr. Albana Greca, MD, MMedSc

Hi Robert,

Your question can be understood in two ways: you may be confused about what the numbers mean, or you may actually feel mentally confused when you wake. These situations require different advice.

What Do Morning Readings of 90–130 Mean?

If the readings were taken after at least eight hours without food or caloric drinks:

• 90–99 mg/dL: within the normal fasting range;


• 100–125 mg/dL: within the prediabetes range;


• 126–130 mg/dL: within the diabetes range if confirmed by an approved laboratory test.

A home glucose meter cannot diagnose prediabetes or diabetes. Diagnosis normally requires fasting plasma glucose, HbA1c or an oral glucose tolerance test, and an abnormal result usually needs confirmation.

See our guide to blood tests for diabetes.

What If You Already Have Diabetes?

For many nonpregnant adults who already have diabetes, a common before-meal target is 80–130 mg/dL. In that situation, readings from 90 to 130 may be within the treatment target, although personal goals can differ according to age, medicines, heart or kidney disease and the risk of low glucose.

This treatment target is different from the thresholds used to diagnose diabetes in someone who has not previously been diagnosed.

Compare the ranges in our normal blood sugar level chart.

Could These Numbers Cause Confusion?

Glucose between 90 and 130 mg/dL is not hypoglycemia. Low glucose is generally below 70 mg/dL and can cause sweating, shaking, dizziness, unusual behavior and confusion.

If you are genuinely disoriented, unable to think clearly or difficult to wake despite glucose being 90–130, do not assume the symptom is caused by blood sugar. Other possibilities include sleep apnea, poor sleep, medication effects, alcohol, dehydration, infection, neurological illness or another medical problem.

How Should You Check the Meter?

• Wash and dry your hands before testing.


• Use strips that are not expired and were stored correctly.


• Make sure the strip is compatible with the meter.


• Repeat an unexpected result with a new strip.


• Bring the meter to a medical visit and compare it with a laboratory result when needed.

Blood should not normally collect inside the meter itself. Follow the manufacturer’s cleaning instructions and do not insert liquid into the strip port.

What Testing Would Clarify the Situation?

If fasting readings repeatedly reach 100 mg/dL or higher, ask for laboratory testing. HbA1c is convenient because it does not require fasting and estimates average glucose over the previous two to three months.

• Normal HbA1c: below 5.7%


• Prediabetes: 5.7–6.4%


• Diabetes range: 6.5% or higher when confirmed

Read more in HbA1c explained.

My Advice

Do not label all readings from 90 to 130 as “borderline diabetes.” First confirm that they are truly fasting and obtain a laboratory fasting glucose or HbA1c if the higher values are repeated.

If “confused” means actual mental confusion on waking, arrange a prompt medical assessment even when the glucose reading is normal. Check glucose during the symptom, record medicines and sleep symptoms, and seek emergency care for any sudden neurological warning sign.

Hope this helps.

Dr. Albana Greca

Related Questions

• Is Blood Sugar of 107 or 110 mg/dL High?


• Is Fasting Blood Glucose of 126 mg/dL High?


• Why Can Fasting and Two-Hour Glucose Differ?

Related Resources

• Normal Blood Sugar Level Chart


• Blood Tests for Diabetes


• Low Blood Glucose: Causes and Treatment

References

• NIDDK: Diabetes Tests and Diagnosis


• American Diabetes Association: Blood Glucose Targets


• CDC: Low Blood Sugar and Confusion