Diabetes and Endocrinology
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At a Glance
Q: What is prediabetes and how is it diagnosed?
A: Prediabetes means blood sugar is higher than normal but not yet diabetes. It’s diagnosed with glucose or A1C tests.
- Prediabetes affects millions of Americans.
- Regular checkups catch blood sugar changes early.
- Diet and activity reduce diabetes risk significantly.
Over 38 million Americans have diabetes. That’s nearly the entire population of California.
But combine the populations of California, Ohio, Texas, and New York and you get roughly the number of Americans with prediabetes—about 100 million. As its name suggests, prediabetes means blood sugar levels are higher than normal but not high enough to be considered diabetes. And of those nearly 100 million, about 80% don’t even know they have it.
As the saying goes, “ignorance is bliss,” but it’s important to catch prediabetes early to lower your risk for further health complications.
How is prediabetes diagnosed?
According to Dr. Carlos Ventura, a Years Ahead internal medicine provider, there are two ways to measure blood sugar: a glucose test and an A1C test.
Glucose (sugar) levels range as follows:
- Normal: 70 to 99 milligrams per deciliter (mg/dL)
- Prediabetes: 100 mg/dL to 125 mg/dL
- Diabetes: 126+ mg/dL
A1C (known as glycosylated hemoglobin) is a protein in red blood cells. It attaches to glucose as it circulates in your blood for about two months.
A glucose test tells you your blood sugar level at that moment, but an A1C test gives your average blood sugar level for the past two months.
A1C levels range as follows:
- Normal: 5.5% or lower
- Prediabetes: 5.6% to 6.4%
- Diabetes: 6.5% and higher
For those right on the cusp of diabetes, your doctor might suggest medication to regulate your blood sugar.
Can I reverse prediabetes?
Dr. Ventura often has prediabetic patients who feel trying to prevent diabetes is pointless. If left untreated, prediabetes can quickly turn into diabetes. However, Dr. Ventura has several patients who have managed their prediabetes for decades.
“So why not act upon it instead of just giving up?”
With a few lifestyle changes, you can keep your blood sugar from reaching diabetic levels.
Can be prediabetes be prevented?
While family history is a big risk factor when it comes to type 2 diabetes, so are diet and physical activity.
“I have patients who have family members with diabetes,” Dr. Ventura says, “but they have made changes to the way they eat and are physically active and never get it.”
He suggests eating and drinking fewer carbs and doing something active three to four days a week—whatever that looks like to you.
“If it’s not your couch watching Netflix,” he says, “I’ll take it.”
Why should I be concerned about prediabetes?
Managing your blood sugar levels is important to avoid other health complications. The risk of eye diseases like cataracts, cardiovascular diseases (the leading cause of death), and kidney disease all increase with prediabetes and even more so with diabetes.
Prediabetes is usually asymptomatic, meaning there’s no way to know you have it without a glucose or A1C test. Because of this, regular checkups with your doctor can help you prevent diabetes.
People Often Ask
Prediabetes usually has no symptoms. The only way to know is through a blood test, like fasting glucose or A1C, during a routine checkup.
Prediabetes is 100–125 mg/dL on a glucose test or 5.6–6.4% on an A1C test. Higher numbers may indicate diabetes.
Yes. Eating fewer carbs, staying active most days, and maintaining a healthy weight can lower blood sugar and reduce diabetes risk.
Untreated prediabetes can lead to type 2 diabetes and raise your risk for heart disease, kidney problems, and vision issues.
Adults should ask their doctor about blood sugar testing every 1–3 years, especially if overweight or have a family history of diabetes.
