--- title: "Fasting blood sugar levels: what 99, 100 and 126 mean" description: "The CDC's fasting blood sugar ranges in mg/dL, how to prepare for the test, what can push a result up, and what supplement testimonials leave out." canonical: https://glucosebench.com/fasting-blood-sugar alternate_html: https://glucosebench.com/fasting-blood-sugar language: en-US last_updated: 2026-09-27 type: guia --- # Fasting blood sugar: three cutoffs and one blood draw 1. [Home](https://glucosebench.com/) 2. [Blood sugar basics](https://glucosebench.com/blood-sugar) 3. Fasting blood sugar: three cutoffs and one blood draw A fasting test is the plainest blood sugar number you'll get: no food for eight hours, one draw, one result. Reading it takes three cutoffs, and a high result usually gets a second test before anyone calls it diabetes. By **GlucoseBench editorial team**Updated September 27, 2026 ![Fasting blood sugar: three cutoffs and one blood draw](https://glucosebench.com/img/guia-fasting-blood-sugar-640.webp) Short answer The CDC's cutoffs for fasting blood sugar: 99 mg/dL or below is normal, 100 to 125 mg/dL is prediabetes, and 126 mg/dL or above is diabetes. You fast for at least 8 hours first, with nothing but sips of water, and the draw is usually in the morning. One result in the diabetes range isn't the end of the story, because doctors usually confirm it with a second test. And a meter from the drugstore can't make the diagnosis, says the NIDDK. ## Fasting blood sugar ranges The CDC uses three bands and doesn't grade inside them, so a 101 and a 124 land in the same place. The A1C, glucose tolerance and random test cutoffs sit side by side in our diabetes tests guide. Fasting result CDC category Next step, per NIDDK 99 mg/dL or below Normal With normal results, retest every 3 years 100 to 125 mg/dL Prediabetes Get tested for type 2 diabetes every year 126 mg/dL or above Diabetes Usually confirmed with a second test Sources: CDC, "Diabetes Testing" (May 15, 2024), and NIDDK, "Diabetes Tests & Diagnosis" (last reviewed July 2022), both read on September 27, 2026. The NIDDK table gives the same fasting cutoffs. They apply if you aren't pregnant; some tests use different cutoffs during pregnancy. ## Getting the fasting test right 1. ### Stop eating at least 8 hours before NIDDK defines fasting as "nothing to eat or drink except sips of water." The CDC describes it as an overnight fast. 2. ### Go in the morning "For the most reliable results," NIDDK says, the test is given in the morning after the fast. 3. ### Ask about routine bloodwork Glucose is often part of a standard panel such as the basic metabolic panel (BMP). MedlinePlus says that in that case you may need to fast, and to ask your provider whether you do. ## Reasons a fasting result comes back high ### Prediabetes and diabetes MedlinePlus calls them the most common causes of high glucose levels. ### Other conditions An overactive thyroid, a problem with the pancreas such as pancreatitis, adrenal gland problems including Cushing's syndrome, and stress from surgery, very serious illness or trauma. ### Some medicines MedlinePlus lists certain types of steroids, antipsychotics, beta-blockers and statins as medicines that may cause high blood glucose in some people. Don't stop a prescription over this; bring it up with whoever prescribed it. ### Everyday swings Sickness and stress move glucose results. NIDDK says fasting and glucose tolerance results are also more affected than the A1C by small changes in temperature, equipment or sample handling. ## Fasting numbers in supplement testimonials A customer quoted on the GlucoTrust page had "fasting blood sugar levels that were up in the 170s or 180s." On the CDC's scale, that's in the diabetes band, a number for a doctor's office and not for a sales page. Insufend's page quotes a customer whose "fasting levels started trending downward, and my A1C followed," with no numbers at all. Neither testimonial gives a lab, a date or a second test. The research behind these products is far quieter than the testimonials. Both products list herbs such as gymnema and cinnamon, and NCCIH, the NIH's center for complementary health, says: "We don't have reliable evidence that any herbal supplements can help to control diabetes or its complications." If you're on diabetes medication, clear any supplement with your doctor first, and keep taking what's prescribed unless your doctor changes it. ## Frequently asked questions **What is a normal fasting blood sugar?** 99 mg/dL or below, according to the CDC. From 100 to 125 mg/dL is prediabetes, and 126 mg/dL or above is diabetes. **Is a fasting blood sugar of 110 normal?** No. 110 mg/dL falls in the CDC's prediabetes range of 100 to 125 mg/dL. NIDDK's advice after a prediabetes result is to be retested for type 2 diabetes yearly, and your doctor decides whether to repeat the test or use a different one. **How long do you fast before a fasting blood sugar test?** At least 8 hours, with nothing to eat or drink except sips of water, per NIDDK. Not every glucose test needs it: you can eat before an A1C or a random glucose test. **Is a fasting blood sugar of 126 diabetes?** 126 mg/dL is where the CDC's diabetes range begins. A diagnosis usually rests on a second test, so one result is a reason to see your doctor, not a verdict. **My lab report says "impaired fasting glucose." What does that mean?** None of the government pages we read for this guide uses that phrase, so we won't guess at a definition. Compare the number itself with the CDC's bands above, and ask your doctor what the label means for you. **Can I check my fasting blood sugar at home?** A home meter gives you a reading, and people with diabetes often test at home on their provider's advice. A diagnosis is another matter: it takes a lab draw, and NIDDK is clear that store-bought testing equipment can't provide one. ## Related pages Blood sugar basics ### [Prediabetes: a number worth acting on, usually without a symptom](https://glucosebench.com/prediabetes) Prediabetes means your blood sugar is higher than normal but not high enough for a type 2 diabetes diagnosis. Read more Blood sugar basics ### [Which blood test diagnoses diabetes? All four, compared](https://glucosebench.com/diabetes-tests) Type 2 diabetes and prediabetes are diagnosed with blood tests: the A1C, the fasting plasma glucose test, the oral glucose tolerance test (OGTT) and, when there are… Read more Blood sugar basics ### [Your A1C result, read against the NIH's cutoffs and the CDC's chart](https://glucosebench.com/a1c-levels) A normal A1C is below 5.7%. Read more Blood sugar basics ### [Why your blood sugar is high in the morning, and how to find your own pattern](https://glucosebench.com/morning-blood-sugar) The CDC calls it the dawn phenomenon: "hormones tend to surge early in the morning, and for people with diabetes blood sugar can spike." Sleep counts too: the CDC says… Read more Updated September 27, 2026. 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