A1C and Prediabetes: What Your Blood Sugar Number Means and Who Should Be Screened

What A1C means

A1C, also called hemoglobin A1C or HbA1c, is a blood test that shows your average blood sugar over about the past two to three months. It works because sugar in the blood attaches to hemoglobin, a protein in red blood cells. The more sugar in your blood over time, the higher the A1C percentage tends to be.

A1C is different from a finger-stick blood sugar check at home. A home reading is a snapshot of one moment. A1C gives a longer view, which is why it is commonly used to screen for prediabetes, diagnose diabetes, and monitor known diabetes. The CDC explains A1C testing and MedlinePlus also describes how the hemoglobin A1C test is used.

A1C result	What it usually means
Below 5.7%	Normal range
5.7% to 6.4%	Prediabetes range
6.5% or higher	Diabetes range

These numbers are a starting point, not the whole story. Your clinician may look at your age, medicines, other medical conditions, family history, and whether the result should be repeated.

What prediabetes means

Prediabetes means blood sugar is higher than normal but not high enough to meet the usual criteria for diabetes. It is a warning sign, not a personal failure and not a guarantee that type 2 diabetes will happen.

Prediabetes usually has no clear symptoms. Many people find out only after routine lab work. That is why screening is important for adults with risk factors.

Prediabetes matters because it raises the chance of developing type 2 diabetes. It is also linked with heart and blood vessel risk, so a visit about A1C is often a good time to review blood pressure, cholesterol, weight, physical activity, smoking, sleep, and family history.

Who should be screened

The U.S. Preventive Services Task Force recommends screening adults ages 35 to 70 who have overweight or obesity and do not have symptoms of diabetes. The USPSTF also notes that screening every three years may be reasonable for adults whose blood sugar is normal, though the best interval is not certain.

The CDC also advises A1C testing for adults over age 45, and for younger adults who have overweight plus another risk factor. Risk factors include:

• A parent, brother, or sister with type 2 diabetes
• Physical activity less than three times per week
• A history of gestational diabetes during pregnancy
• A history of polycystic ovary syndrome, often called PCOS
• High blood pressure
• Belonging to a group with a higher burden of diabetes, including Black, Hispanic/Latino, American Indian, Alaska Native, Pacific Islander, and some Asian American communities

For Asian American adults, clinicians may consider screening at a lower body mass index because diabetes risk can occur at lower weight levels.

How prediabetes is confirmed

A1C is one screening option, but it is not the only one. Other blood sugar tests include fasting plasma glucose, which checks blood sugar after an overnight fast, and an oral glucose tolerance test, which checks how the body handles sugar over a few hours.

Diabetes testing often needs confirmation. The American Diabetes Association notes that diagnosis usually requires repeat testing on another day, unless blood sugar is very high or classic symptoms are present along with a positive test.

A1C can also be less accurate in some situations. Tell your clinician if you have severe anemia, kidney failure, liver disease, sickle cell disease, thalassemia, recent blood loss, a recent blood transfusion, pregnancy, or if you take medicines that may affect A1C. In those cases, another test may give a clearer picture.

Next steps to lower your risk

If your A1C is in the prediabetes range, the next step is usually a plan, not panic. The CDC’s prediabetes prevention guidance focuses on proven lifestyle changes, including regular physical activity and weight loss when a person has overweight.

Useful first steps include:

• Confirm the result and ask when to repeat testing.
• Review your current eating pattern rather than starting a crash diet.
• Build toward regular activity, such as brisk walking, if it is safe for you.
• Ask what amount of weight loss, if any, would be realistic and medically appropriate.
• Check blood pressure and cholesterol, since these often affect the same long-term health risks.
• Ask whether a structured Diabetes Prevention Program is available through your insurance, employer, community, or online.

The CDC describes a common prevention goal as losing about 5% to 7% of body weight for people with overweight and getting at least 150 minutes per week of brisk walking or a similar activity. If those goals feel far away, start smaller. A plan you can keep is better than an intense plan that lasts two weeks.

In San Bernardino County

For patients in San Bernardino County, the California Department of Public Health lists A1C, fasting blood sugar, glucose tolerance testing, and random blood sugar testing as ways clinicians evaluate diabetes risk. CDPH also describes statewide diabetes prevention work focused on healthy eating, physical activity, tobacco cessation, and prevention and control of overweight and obesity. You can read the state’s Diabetes Prevention information for more background.

When to see a doctor

Make an appointment if you were told your A1C is high, if you have not been screened and meet the risk factors above, or if you are unsure what your lab result means. Adults in Upland and Rancho Cucamonga can review A1C, weight, blood pressure, cholesterol, medications, and family history during a primary care visit.

Call sooner if you have symptoms that can occur with diabetes, such as frequent urination, unusual thirst or hunger, blurry vision, fatigue, unexplained weight loss, slow-healing sores, numbness or tingling in the hands or feet, or frequent urinary or yeast infections. Seek urgent or emergency care for severe symptoms such as confusion, repeated vomiting, extreme weakness, deep or rapid breathing, or signs of dehydration, especially if you have known diabetes or a very high home blood sugar reading.

Elite Family Medical Center offers diabetes care for patients who need screening, follow-up, or an ongoing plan. To discuss your A1C or prediabetes risk with Maher Danhash, MD, you can call the office or request a visit.

We see patients for this at our Upland and Rancho Cucamonga offices. Request a visit or call either office.