by Julia
QUESTION: I am 18 years old and worried because my fasting blood glucose was 98 mg/dL. Is this level high, and what should I do?
A fasting laboratory glucose of 98 mg/dL is within the normal range. Prediabetes begins at 100 mg/dL, and diabetes begins at 126 mg/dL when confirmed. This result does not suggest diabetes and does not require a special diet, supplements, an oral glucose tolerance test, or repeated home testing unless you have important risk factors, symptoms, or different advice from your clinician.
Answer by Dr. Albana Greca, MD, MMedSc
Hi Julia,
Your result is reassuring. For a fasting plasma glucose test, fasting generally means no food or caloric drinks for at least eight hours. A value of 98 mg/dL is below the prediabetes threshold.
For nonpregnant people, laboratory fasting plasma glucose is generally interpreted as:
Your reading of 98 mg/dL is normal. It is close to 100, but diagnostic limits are not pass-or-fail measures of health where a one-point difference means something suddenly went wrong. Glucose varies naturally with sleep, stress, illness, recent activity, fasting duration, and laboratory variation.
You can compare these results with our guide to normal fasting blood sugar ranges.
Not usually because of this result alone. An HbA1c or oral glucose tolerance test may be appropriate when someone has an abnormal screening result, symptoms, pregnancy-related concerns, or significant risk factors. A normal fasting glucose of 98 mg/dL does not automatically require those tests.
Testing may be discussed sooner if you have a strong family history of diabetes, overweight or increased waist size, polycystic ovary syndrome, previous gestational diabetes, high blood pressure, abnormal cholesterol, or medicines that can raise glucose. Our page on blood tests for diabetes explains when different tests are used.
No. Diabetes can be present without obvious symptoms, and symptoms are not required when laboratory criteria are met and confirmed. Conversely, the absence of symptoms does not change an abnormal laboratory result.
Classic symptoms can include increased thirst, frequent urination, blurred vision, fatigue, recurrent infections, and unexplained weight loss. There is no requirement to drink five to seven liters of water before thirst is considered important.
No treatment is needed for a fasting glucose of 98 mg/dL. Continue ordinary health habits: eat balanced meals, stay physically active, sleep adequately, avoid smoking, and attend routine medical care. You do not need an extreme low-carbohydrate diet or glucose-lowering herbs.
Avoid checking repeatedly out of fear. Home glucose meters have normal measurement variation and are not used to diagnose diabetes. Repeated unnecessary testing can create more anxiety without providing useful medical information.
If your doctor ordered this test because of a specific condition or family risk, ask when routine screening should be repeated. Otherwise, follow the screening schedule recommended for your age and personal risk rather than testing every few days.
Arrange medical review if you develop persistent excessive thirst, frequent urination, blurred vision, recurrent infections, or unexplained weight loss, or if a future laboratory fasting glucose reaches 100 mg/dL or higher. Seek urgent care for severe illness with very high glucose, vomiting, difficult breathing, confusion, or fainting.
A fasting glucose of 98 mg/dL is normal and should be reassuring. No special diabetes treatment or additional testing is needed solely because of this number. Discuss future screening with your clinician only if you have symptoms, important risk factors, or another abnormal result.
Educational safety note: This answer is for general diabetes education only. It does not replace personal medical advice, diagnosis, or treatment. Do not start medicines, supplements, restrictive diets, or intensive exercise plans because of one glucose result without speaking with your healthcare provider.
Last reviewed: July 2026.
Click here to post comments or follow up
Ask the Doctor now? Simply click here to return to Blood Sugar Charts & Normal Ranges.