Prediabetes usually has no signs or symptoms at all. That’s the most important thing to know, and it’s the reason 8 in 10 adults with prediabetes don’t know they have it. More than 115 million American adults are currently living with the condition, and the vast majority found out only through routine blood work, not because something felt wrong.
Still, there are subtle physical changes that can show up during this stage, and recognizing them matters. Prediabetes is the window where blood sugar is elevated but hasn’t crossed into type 2 diabetes territory, and it’s the best time to reverse course.
Why Prediabetes Is Usually Silent
In the prediabetic phase, your body is producing extra insulin to compensate for cells that have become less responsive to it. For a while, this workaround keeps blood sugar close enough to normal that you feel fine. Your pancreas is working harder than it should, but the system hasn’t broken down yet.
The classic diabetes symptoms people associate with high blood sugar, like excessive thirst, frequent urination, blurred vision, and unexplained weight loss, generally don’t appear until blood sugar climbs higher, into the type 2 diabetes range. If you’re experiencing those symptoms, it may mean you’ve already progressed past prediabetes.
Subtle Signs That Can Appear
While most people with prediabetes feel perfectly normal, a few physical changes can occur during this stage:
Darkened skin patches. One of the few visible signs linked to insulin resistance is a condition that causes dark, thick, velvety patches of skin in body folds and creases. It most often appears on the back of the neck, in the armpits, or in the groin. The affected skin may feel itchy, develop an odor, or sprout small skin tags. This happens because excess insulin in the bloodstream stimulates skin cell growth. If you notice these patches, it’s worth getting your blood sugar checked.
Fatigue after meals. When your cells don’t respond well to insulin, sugar has a harder time getting from your bloodstream into your cells for energy. This can leave you feeling unusually tired, particularly after eating carbohydrate-heavy meals. Many people dismiss this as normal sluggishness, but persistent post-meal fatigue can be an early clue.
Mild changes in vision. Elevated blood sugar pulls fluid from tissues throughout the body, including the lenses of your eyes. This can temporarily affect your ability to focus. In prediabetes, these shifts tend to be subtle and intermittent rather than constant.
Signs You May Have Crossed Into Type 2
If prediabetes progresses, the symptoms become harder to ignore. Increased thirst, frequent urination (especially at night), persistent hunger even after eating, numbness or tingling in your hands or feet, slow-healing cuts, and frequent infections all suggest blood sugar has risen beyond the prediabetic range. These symptoms develop because the pancreas can no longer produce enough insulin to keep up with your body’s needs, and blood sugar stays chronically elevated.
How Prediabetes Is Actually Diagnosed
Because symptoms are unreliable, diagnosis depends on blood tests. Three tests can identify prediabetes, and each measures blood sugar differently:
- A1C test: Reflects your average blood sugar over the past two to three months. A result between 5.7% and 6.4% indicates prediabetes.
- Fasting blood glucose: Measures blood sugar after an overnight fast. A reading of 100 to 125 mg/dL falls in the prediabetic range.
- Oral glucose tolerance test: Measures blood sugar two hours after drinking a sugary solution. A result between 140 and 199 mg/dL signals prediabetes.
Your doctor may use one or more of these tests. It’s common for results to differ slightly between them, so a second test is often used to confirm.
What’s Happening Inside Your Body
Prediabetes starts when your muscles, liver, and fat tissue become less responsive to insulin. In a healthy body, insulin acts like a key that unlocks cells so they can absorb sugar from the bloodstream. When that key stops working well, your pancreas responds by pumping out more and more insulin to force the same result.
This overproduction keeps blood sugar in check for a while, but it puts chronic stress on the insulin-producing cells in your pancreas. Over time, those cells wear out. Meanwhile, the liver, which normally stores sugar and releases it as needed, starts overproducing glucose because it’s no longer responding properly to insulin’s “stop” signal. That combination of failing production and rising output is what pushes blood sugar from the prediabetic range into full diabetes.
Who Should Get Tested
Given that prediabetes rarely announces itself, screening is the only reliable way to catch it. You’re at higher risk if you carry extra weight (particularly around the midsection), are over 35, have a parent or sibling with type 2 diabetes, are physically inactive, or have a history of gestational diabetes. People of Black, Hispanic, Native American, Asian American, or Pacific Islander descent also face elevated risk.
If none of those apply to you, routine screening is still recommended starting at age 35. If your results are normal, repeat testing every three years is typical.
Prediabetes Can Be Reversed
Unlike many health conditions, prediabetes gives you a genuine opportunity to change direction. Data from the Diabetes Prevention Program, one of the largest studies on the topic, showed that losing about 7% of body weight and increasing physical activity reduced the risk of progressing to type 2 diabetes by 58%. For someone weighing 200 pounds, that’s roughly 14 pounds.
The changes that matter most are straightforward: regular movement (even brisk walking counts), reducing refined carbohydrates and added sugars, and modest, sustained weight loss. These interventions work by making your cells more responsive to insulin again, easing the burden on your pancreas before permanent damage sets in. The earlier you catch prediabetes, the easier it is to pull your numbers back into the normal range.