What Are Normal Blood Sugar Levels?

Normal blood sugar – Person testing blood sugar at home
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Fasting blood sugar levels may vary based on factors like alcohol consumption, antibiotics, and blood insulin levels.
Age, medical history, sex, and medications can affect blood sugar levels.
High blood sugar levels indicate prediabetes and put you at risk for diabetes; low blood sugar levels are also dangerous.
Generally, a normal blood sugar range is about 70-100 mg/dL.1 Monitoring your blood sugar can help prevent serious complications if you have diabetes.23

How To Tell If Your Blood Sugar Is Normal
Multiple factors can affect your blood sugar, including alcohol consumption, certain antibiotics, and the amount of insulin in your bloodstream.4 Insulin is a hormone that helps regulate blood glucose levels.

Normal blood sugar levels for people without diabetes and recommended target ranges for people with diabetes can vary based on factors like:2

Age
Illness
Level of physical activity
Medications
Stress
The following chart includes general guidelines for blood sugar levels measured in milligrams per deciliter (mg/dL).156

Age Normal Fasting Glucose Without Diabetes Target Glucose Range for Type 1 Diabetes Before Meals Target Glucose Range for Type 1 Diabetes at Bedtime
Adults and Children 13-19 70-100 mg/dL 90-130 mg/dL 90-150 mg/DL
Children 6-12 70-100 mg/dL 90-180 mg/DL 100-180 mg/DL
Children Under 6 70-100 mg/dL 100-180 mg/DL 110 to 200 mg/DL
How Is Blood Sugar Tested?
A healthcare provider may recommend one or more tests to measure your blood sugar.

These tests can help diagnose prediabetes or diabetes. Prediabetes means your blood sugar is higher than normal but not high enough to be diagnosed with diabetes.