Prediabetes can be difficult to recognize for one important reason: most people do not have noticeable symptoms.
You can feel perfectly healthy while your blood sugar is already higher than normal.
That is why waiting for symptoms is not a reliable way to detect prediabetes. Blood testing is the only way to know for sure.
Some people do develop physical signs associated with insulin resistance, such as darkened patches of skin. And symptoms such as excessive thirst, frequent urination, blurred vision, or unexplained weight loss can occur when blood sugar becomes more elevated.
But those symptoms should not simply be assumed to mean prediabetes. They can indicate that blood glucose has risen into the diabetes range or may have another cause that needs medical evaluation.
Understanding that distinction can help you recognize when testing is appropriate without assuming that every common symptom means you have a blood sugar problem.
Quick Answer: What Are the Symptoms of Prediabetes?
Prediabetes usually causes no obvious symptoms. Many people discover they have it only after a routine blood test.
Some people with insulin resistance may develop acanthosis nigricans, which causes dark, thickened, velvety patches of skin, often around the neck, armpits, or groin.
Symptoms commonly associated with high blood sugar, such as increased thirst, frequent urination, blurred vision, fatigue, or unexplained weight loss, may occur when glucose becomes more elevated. If you develop these symptoms, talk with a healthcare professional rather than assuming they are simply signs of prediabetes.
Key Takeaways
- Most people with prediabetes have no noticeable symptoms.
- You cannot determine whether you have prediabetes based on how you feel.
- Acanthosis nigricans can be a visible sign of insulin resistance in some people.
- Excessive thirst, frequent urination, blurred vision, and unexplained weight loss are more characteristic of significant hyperglycemia or diabetes than uncomplicated prediabetes.
- Fatigue and hunger have many possible causes and cannot diagnose prediabetes.
- Blood testing is the only reliable way to determine whether your glucose is in the prediabetes range.
- If you have risk factors for type 2 diabetes, screening can be important even when you feel completely healthy.
Does Prediabetes Have Symptoms?
Usually, no.
This is one of the most important facts to understand about prediabetes.
Prediabetes develops when blood glucose rises above the normal range but has not reached the level used to diagnose diabetes.
The increase is often gradual, and it frequently occurs without producing noticeable changes in how you feel.
You might have prediabetes for years without knowing it.
That is why phrases such as “early symptoms of prediabetes” or “prediabetes warning signs” can be misleading. There isn’t a dependable set of symptoms that appears when someone crosses from normal blood glucose into the prediabetes range.
Instead, prediabetes is identified through blood tests such as A1C, fasting plasma glucose, or an oral glucose tolerance test.
If you want to understand those numbers, what causes prediabetes, and what to do after a diagnosis, see our complete guide to What Is Prediabetes?.
Why Prediabetes Can Go Unnoticed
Prediabetes often develops alongside insulin resistance.
Insulin is a hormone that helps glucose move from your bloodstream into your cells. When your cells become less responsive to insulin, your pancreas may initially compensate by producing more of it.
For a while, this compensation can keep glucose relatively close to the normal range.
As insulin resistance progresses, however, your body may have increasing difficulty regulating glucose. Blood sugar can gradually move into the prediabetes range and, in some people, eventually into the type 2 diabetes range.
None of this necessarily produces symptoms you can feel.
You may continue working, exercising, eating, and going about your normal routine without realizing your glucose has changed.
That is precisely why screening is more dependable than symptom watching for detecting prediabetes.
Are There Any Physical Signs of Prediabetes?
Although prediabetes itself usually does not produce recognizable symptoms, some people have physical signs associated with the underlying insulin resistance.
The most notable is acanthosis nigricans.
Dark, Velvety Patches of Skin
Acanthosis nigricans causes areas of skin to become darker, thicker, and sometimes velvety in texture.
It commonly develops:
- On the back or sides of the neck
- In the armpits
- Around the groin
- In other body folds or creases
Acanthosis nigricans is associated with insulin resistance and is more common in people with obesity and type 2 diabetes.
However, having darkened skin does not prove that you have prediabetes.
Acanthosis nigricans can have other causes, and changes in skin pigmentation can occur for many reasons.
If you notice new areas of thickened, darkened skin, particularly around the neck or body folds, mention them to your healthcare provider.
Are Skin Tags a Sign of Prediabetes?
Skin tags are small, soft, usually harmless growths that often develop around the neck, armpits, groin, or other areas where skin rubs together.
Studies have found associations between multiple skin tags and insulin resistance or metabolic conditions.
But skin tags are also extremely common in people who do not have prediabetes.
So you should not look at a skin tag and conclude that your blood sugar is elevated.
If you have numerous skin tags along with other risk factors for type 2 diabetes, it may be reasonable to discuss diabetes screening with your healthcare provider.
What Symptoms Can Occur When Blood Sugar Gets Higher?
This is where an important distinction needs to be made.
Several symptoms commonly described online as “prediabetes symptoms” are actually classic symptoms of hyperglycemia and diabetes.
They can occur when blood glucose becomes sufficiently elevated, but they are not reliable signs that someone merely has prediabetes.
If you experience them, particularly when several occur together, getting your blood sugar tested is more useful than trying to determine whether you have prediabetes based on symptoms.
Increased Thirst
Excessive or unusual thirst can occur when blood glucose becomes high.
When enough glucose builds up in the bloodstream, the kidneys try to remove more glucose through the urine. This can increase fluid loss and leave you feeling unusually thirsty.
Persistent thirst that represents a noticeable change from your normal habits deserves attention, particularly when accompanied by frequent urination.
Frequent Urination
Frequent urination is another classic symptom of elevated blood glucose.
You may notice that you need to use the bathroom much more frequently or that you are waking during the night to urinate.
There are many other possible causes of frequent urination, including medications, urinary problems, increased fluid intake, and other medical conditions.
But frequent urination combined with excessive thirst is a good reason to talk with your healthcare provider about blood glucose testing.
Blurred Vision
Changes in blood glucose can temporarily affect fluid balance in the eye and alter vision.
You might notice that your vision becomes blurry or that focusing seems more difficult than usual.
Blurred vision has many possible causes, however, and should never be self-diagnosed as prediabetes.
New, persistent, or sudden vision changes should be medically evaluated.
Unexplained Weight Loss
Unintentional weight loss is not a typical early sign of prediabetes.
It is more concerning for diabetes when insulin is insufficient or glucose cannot be used normally for energy.
If you are losing weight without deliberately changing your diet or activity level, particularly if you also have excessive thirst or frequent urination, contact your healthcare provider.
Increased Hunger
Some people with diabetes experience increased hunger, but hunger by itself tells you very little about your blood sugar.
Appetite can be affected by meal composition, activity, sleep, stress, medications, and many other factors.
Persistent or unusual hunger may deserve investigation, but it should not be considered a reliable prediabetes symptom.
Is Fatigue a Symptom of Prediabetes?
Fatigue deserves special attention because it is frequently included on lists of prediabetes symptoms.
Feeling unusually tired can occur in people who have blood sugar problems, but fatigue is extremely nonspecific.
It can also be caused by:
- Poor sleep
- Stress
- Anemia
- Thyroid disorders
- Infections
- Depression
- Certain medications
- Sleep apnea
- Numerous other medical conditions
So fatigue alone is a poor indicator of prediabetes.
If you have persistent unexplained fatigue, particularly when combined with diabetes risk factors or other symptoms of high blood sugar, discuss it with your healthcare provider.
Are Tingling or Numb Feet a Sign of Prediabetes?
Tingling, burning, pain, or numbness in the hands or feet can have many causes.
Peripheral neuropathy is strongly associated with diabetes, but research also suggests that nerve abnormalities can occur in some people with prediabetes, particularly when other metabolic risk factors are present.
That does not mean tingling feet are a dependable way to identify prediabetes.
Nerve symptoms can result from vitamin deficiencies, compressed nerves, thyroid disease, medication effects, alcohol use, circulation problems, and many other conditions.
Persistent numbness, tingling, burning, or pain should therefore be evaluated rather than attributed automatically to blood sugar.
Is Slow Wound Healing a Prediabetes Symptom?
Slow-healing wounds are commonly associated with diabetes, particularly when blood glucose has been elevated for an extended period.
Poor glucose control can contribute to circulation problems, nerve damage, and impaired immune function, all of which can interfere with healing.
But slow wound healing is not a reliable early symptom of prediabetes.
A wound that is not healing normally deserves medical attention regardless of whether you have been diagnosed with diabetes.
This is particularly important for wounds on the feet.
Prediabetes Symptoms vs. Type 2 Diabetes Symptoms
The difference between prediabetes and type 2 diabetes is determined by blood glucose levels, not by the number or severity of symptoms you have.
Someone with prediabetes can have no symptoms at all.
Someone with newly diagnosed type 2 diabetes can also have no symptoms.
When glucose becomes more substantially elevated, however, classic diabetes symptoms become more likely.
| Prediabetes | Higher Blood Sugar/Diabetes |
|---|---|
| Usually no noticeable symptoms | Increased thirst may occur |
| Often discovered through screening | Frequent urination may occur |
| Acanthosis nigricans may indicate insulin resistance | Blurred vision may occur |
| Risk factors may be the only clue | Unexplained weight loss can occur |
| Blood testing is required for diagnosis | Fatigue or increased hunger may occur |
This is why symptoms cannot tell you whether your glucose falls into the normal, prediabetes, or diabetes range.
Only appropriate testing can do that.
For a broader look at symptoms that can occur when diabetes develops, see our guide to the Warning Signs of Diabetes.
Can You Have Prediabetes Without Knowing It?
Absolutely.
In fact, having no symptoms is typical.
You may have prediabetes while:
- Feeling energetic
- Maintaining your usual weight
- Having normal thirst
- Urinating normally
- Seeing clearly
- Experiencing no obvious health problems
Feeling well does not guarantee that your blood glucose is normal.
The decision to get screened should therefore be based primarily on age, risk factors, medical history, and healthcare recommendations, not on whether you notice symptoms.
Who Should Consider Prediabetes Testing?
Screening recommendations vary somewhat depending on the organization and individual circumstances, but routine screening is generally recommended for adults beginning around age 35.
Earlier testing may be appropriate if you have overweight or obesity along with additional risk factors for type 2 diabetes.
Risk factors can include:
- A parent or sibling with diabetes
- Physical inactivity
- High blood pressure
- Unhealthy cholesterol or triglyceride levels
- Polycystic ovary syndrome
- Cardiovascular disease
- A history of gestational diabetes
- Other conditions associated with insulin resistance
Age and body composition can both influence diabetes risk. You can learn more in How Age and Obesity Affect Diabetes Risk.
Your healthcare provider can determine when testing is appropriate based on your individual circumstances.
How Do You Know for Sure if You Have Prediabetes?
You need a blood test.
Prediabetes can be identified using:
- An A1C test
- A fasting plasma glucose test
- A 2-hour oral glucose tolerance test
These tests measure glucose in different ways.
For most nonpregnant adults, an A1C from 5.7% to 6.4%, fasting plasma glucose from 100 to 125 mg/dL, or a two-hour oral glucose tolerance result from 140 to 199 mg/dL falls within the prediabetes range.
You should not try to diagnose yourself from symptoms or a single home glucose meter reading.
Your healthcare provider can order the appropriate testing and interpret the results in the context of your overall health.
When Should You Talk to Your Doctor?
Consider talking with your healthcare provider about prediabetes testing if you have risk factors, even when you feel completely healthy.
You should also seek medical evaluation if you develop symptoms that could indicate substantially elevated blood glucose, particularly:
- Persistent excessive thirst
- Frequent urination
- Unexplained weight loss
- Persistent blurred vision
- Unusual fatigue combined with other symptoms
These symptoms do not necessarily mean you have diabetes, but they are worth investigating.
If you already know that you have prediabetes, keep up with the follow-up testing recommended by your healthcare provider rather than waiting for symptoms to appear.
What Should You Do if Testing Shows Prediabetes?
A prediabetes diagnosis means your glucose is elevated, but progression to type 2 diabetes is not inevitable.
Lifestyle changes can substantially reduce the risk of developing type 2 diabetes, and some people can return their glucose to levels below the prediabetes range.
Your next steps may include changes to:
- Food choices
- Physical activity
- Weight, when appropriate
- Sleep
- Smoking
- Other cardiovascular and metabolic risk factors
Some people at particularly high risk may also benefit from medication such as metformin.
Rather than trying to cover all of those subjects here, our What Is Prediabetes? guide explains what a diagnosis means and what you can do next.
Frequently Asked Questions
What are the first symptoms of prediabetes?
Most people with prediabetes have no symptoms, so there may be no “first symptom.” Prediabetes is usually discovered through blood testing. Some people with insulin resistance develop acanthosis nigricans, which causes darkened, thickened areas of skin.
Can prediabetes cause frequent urination?
Frequent urination is more strongly associated with significant hyperglycemia and diabetes than uncomplicated prediabetes. If you are urinating much more frequently than usual, particularly if you are also unusually thirsty, talk with your healthcare provider.
Does prediabetes make you tired?
Some people with blood sugar problems experience fatigue, but tiredness has many possible causes and is not a reliable way to identify prediabetes. Persistent unexplained fatigue should be evaluated based on your overall health and other symptoms.
Can prediabetes cause blurred vision?
Blurred vision can occur when blood glucose becomes elevated, but it is not a dependable symptom of prediabetes. New or persistent changes in vision should be evaluated by a healthcare professional.
Can prediabetes cause tingling in your feet?
Some research has found nerve abnormalities in people with prediabetes, but tingling and numbness have many possible causes. Persistent symptoms should be medically evaluated rather than assumed to be caused by prediabetes.
Can you have prediabetes without any symptoms?
Yes. This is very common. You can have prediabetes and feel completely normal, which is why screening is important when you have risk factors.
Is borderline diabetes the same as prediabetes?
“Borderline diabetes” is an informal term commonly used to describe prediabetes. Prediabetes is the preferred medical term for glucose levels that are above normal but below the diabetes range.
How can I tell if prediabetes has become diabetes?
You cannot reliably tell from symptoms alone. Blood testing is required. If you have already been diagnosed with prediabetes, regular follow-up testing can identify whether your glucose has improved, remained stable, or progressed into the diabetes range.
Final Thoughts
The most important symptom of prediabetes may be no symptom at all.
Prediabetes frequently develops silently, so feeling healthy does not necessarily mean your blood glucose is within the normal range.
Some physical signs, particularly acanthosis nigricans, can be associated with insulin resistance. But symptoms such as excessive thirst, frequent urination, blurred vision, and unexplained weight loss are more concerning for significantly elevated blood glucose and should prompt medical evaluation.
Instead of waiting for symptoms, pay attention to your risk factors and follow recommended screening guidelines.
A simple blood test can identify prediabetes long before you would necessarily notice anything is wrong, giving you an opportunity to take action before type 2 diabetes develops.