There is a number that sits quietly in a lot of teenagers’ charts, and most parents never see it. It is not weight. It is not blood pressure. It is a blood sugar number — and it is the earliest honest warning a family gets that a child’s body is starting to struggle with insulin.

The number is prediabetes. Blood sugar higher than normal, not yet high enough to be called type 2 diabetes. And it is far more common in teenagers than most families expect. In a CDC analysis of national survey data from 2005 to 2016, published in JAMA Pediatrics, 18 percent of U.S. adolescents ages 12 to 18 had prediabetes — about one in five. Among young adults 19 to 34, it was 24 percent. Those figures come from 2005–2016 testing, so they are more than three years old, and nothing since suggests the trend reversed.

Why you have probably never seen it

Prediabetes has no symptoms. That is the whole problem. The American Diabetes Association says it plainly: there are no clear symptoms of prediabetes, so a person can have it and not know. A teenager with prediabetes plays sports, goes to school, argues about chores. Nothing looks wrong. It shows up only if someone draws blood and looks.

And blood usually is not drawn, because a routine sports physical does not include a blood sugar test. If your child has never had an A1C or a fasting glucose run, then no one — not you, not the clinic — knows this number.

The three tests, and the numbers that mean prediabetes

These are the standard adult and adolescent thresholds published by the American Diabetes Association:

Test	Normal	Prediabetes	Diabetes
A1C (3-month average)	Below 5.7%	5.7% to 6.4%	6.5% or higher
Fasting plasma glucose	Below 100 mg/dL	100 to 125 mg/dL	126 mg/dL or higher
2-hour glucose tolerance test	Below 140 mg/dL	140 to 199 mg/dL	200 mg/dL or higher

The A1C is the easiest one to ask for. It does not require fasting, and it reports an average of roughly the last three months rather than one morning’s snapshot.

Who should be screened

You do not have to guess. The ADA’s Standards of Care in Diabetes — 2025 recommends risk-based screening for prediabetes or type 2 diabetes after the onset of puberty or after age 10, whichever comes first, in children and adolescents with overweight (BMI at or above the 85th percentile) or obesity (95th percentile or above), who also have at least one additional risk factor. Those additional risk factors include a parent, grandparent or sibling with type 2 diabetes, a mother who had gestational diabetes while carrying that child, certain ancestries with higher risk (including Hispanic and Latino, Black, American Indian and Asian American), and physical signs of insulin resistance — things like a dark velvety patch on the neck.

Read that list once more with your own family in mind. In the Coastal Bend, a great many children meet it. The 2025 Corpus Christi–Nueces County Community Health Assessment reports that 15.5 percent of adults in this county have diagnosed diabetes, against 13.4 percent in Texas and 10.8 percent nationally (CDC PLACES/BRFSS, 2021–2022 data). A county where one adult in six carries a diabetes diagnosis is a county full of children with a family history.

What to say at the next appointment

You do not need medical vocabulary. One sentence works:

“There is type 2 diabetes in our family. Should my child have an A1C or a fasting glucose checked this year?”

That is it. The clinician decides whether the test is warranted — that is their job, not yours. Yours is to make sure the question gets asked, because a well child visit can easily go by without it. Write the result down when you get it, with the date, and keep it. A single A1C is a data point. Two, a year apart, is a direction.

If the number comes back high

Two things are true at once, and both matter.

First, this is not a verdict. Prediabetes is the stage where change still works. The National Institute of Diabetes and Digestive and Kidney Diseases is direct about it: many people can take steps to prevent or delay prediabetes and type 2 diabetes, and for some people blood glucose returns to the normal range.

Second, do not treat it as nothing. The same JAMA Pediatrics analysis found that adolescents and young adults with prediabetes already carried an unfavorable cardiometabolic profile — higher non-HDL cholesterol, higher systolic blood pressure, more central fat, lower insulin sensitivity — than peers with normal glucose. The body is already under load. That is exactly why the window is worth using.

What actually moves those numbers in a child is unglamorous and familiar: daily movement, real food, sleep, and less sugar in liquid form. Not a diet handed to a 13-year-old. A household that changes with them.

This is the whole reason Ignite Fit exists

Ignite Fit is a 10-week season for children ages 8 to 17 in Corpus Christi, built around three blocks each week: movement, a teaching kitchen, and time for faith and encouragement. Families come with the child, because a child cannot change a kitchen alone. Prayer is offered and never required — we are Catholic in who we are, and open to every family regardless of what they believe.

We are not a clinic and we do not diagnose anything. What we can do is walk beside your family in the years where habits are still forming, and make sure the question above gets asked.

If you want your child in the next season, start at Get Help — it takes a few minutes and costs your family nothing. And if you want the local numbers behind all of this, they are on our Community Health page.