- Most people with prediabetes have no symptoms at all. That is why more than 8 in 10 do not know they have it.
- A few notice subtle clues, such as dark, velvety skin patches or tiredness after meals.
- Thirst, frequent urination and blurred vision usually mean blood sugar has risen into the diabetes range.
- The only reliable way to know is a blood test.
Prediabetes develops slowly and quietly. Blood sugar is only slightly above normal, which is not enough to cause the classic symptoms of diabetes. Many people feel perfectly well and only find out after a routine check-up. This silence is exactly why prediabetes is easy to miss, and why knowing your risk and getting tested matters so much.
The silent condition
CDC National Diabetes Statistics Report; Tabák et al., Lancet 2009.
Why there are so few symptoms
Your body is very good at coping with small rises in blood sugar. In prediabetes, fasting glucose is typically between 100 and 125 mg/dL, only a little above normal. The kidneys do not start spilling sugar into the urine until blood sugar is well above 180 mg/dL, so the classic warning signs of thirst and frequent urination simply do not appear. Meanwhile, the pancreas keeps producing extra insulin to hold things steady. You feel fine, yet the strain on your body is quietly building, affecting blood vessels, the liver and the pancreas itself. This is why doctors test people based on risk, not symptoms.
Subtle signs some people notice
None of these signs proves you have prediabetes, and many people have none of them. But if you notice one, it is a good reason to ask for a blood test.
Darker, thicker patches on the back of the neck, armpits, groin or knuckles (acanthosis nigricans) are a sign of high insulin levels.
Many small skin tags on the neck, eyelids or armpits are more common in people with insulin resistance.
Feeling very sleepy after carb-heavy meals, or cravings soon after eating, can happen when blood sugar swings more than normal.
Weight gain around the middle often goes hand in hand with insulin resistance, even if total weight changes little.
High blood pressure, high triglycerides, low HDL cholesterol or a fatty liver on a scan often travel with prediabetes.
Irregular periods from polycystic ovary syndrome, or diabetes during a past pregnancy, raise the chance of prediabetes.
Symptoms that suggest blood sugar is higher
When blood sugar climbs into the diabetes range, the kidneys start passing sugar into the urine and the classic symptoms appear. If you notice these, see a doctor soon rather than waiting for your next check-up.
| Symptom | Why it happens |
|---|---|
| Very thirsty | The body loses extra water through urine and tries to replace it. |
| Urinating often, including at night | The kidneys flush out excess sugar, taking water with it. |
| Blurred vision | High sugar changes the fluid in the lens of the eye. |
| Cuts that heal slowly, frequent infections | High sugar slows healing and helps germs, including thrush, grow. |
| Tiredness and unexplained weight loss | Cells cannot use glucose properly, so the body breaks down fat and muscle. |
| Tingling in the hands or feet | Long-term high sugar can irritate nerves. |
Learn more in Early Signs and Symptoms of Type 2 Diabetes.
Who should pay extra attention
Subtle signs deserve more weight if you also have risk factors: a parent or sibling with type 2 diabetes, South Asian, Black, Hispanic or Indigenous heritage, a past pregnancy with gestational diabetes, polycystic ovary syndrome, high blood pressure, or a waist more than half your height. In these groups, prediabetes often appears at a younger age and a lower weight.
What to do if you are worried
From “I wonder” to knowing
- Try our Diabetes Risk Check to see if testing is recommended.
- Ask your doctor for an HbA1c or fasting glucose test. No special preparation is needed for HbA1c.
- If you are 35 or older, or overweight with another risk factor, get tested even without symptoms.
Get medical help the same day if you have extreme thirst, are passing large amounts of urine, are vomiting, feel confused or very drowsy, or are losing weight quickly without trying. These can be signs of very high blood sugar.
MythI feel fine, so my blood sugar must be normal.
FactPrediabetes and even early type 2 diabetes usually feel like nothing at all. Feeling well is not the same as being tested.
Common questions
Do dark skin patches always mean prediabetes?
No. Acanthosis nigricans is strongly linked with high insulin levels, but it can also run in families or be caused by some medicines and hormone conditions. It is still worth a blood test.
Can prediabetes make me feel tired?
Some people report tiredness, but it has many causes, including poor sleep, low iron and thyroid problems. Do not rely on how you feel; a blood test gives the answer.
If I have no symptoms, how often should I be tested?
If your first test is normal and you are at average risk, every 3 years. If you have prediabetes, every year.
Already diagnosed with type 2 diabetes? Read Early Signs and Symptoms of Type 2 Diabetes in our 18-part Type 2 Diabetes Basics series.
- Prediabetes is usually silent; most people have no symptoms.
- Dark velvety skin, skin tags and a growing waist are subtle clues.
- Thirst, frequent urination and blurred vision suggest blood sugar is in the diabetes range.
- A blood test is the only reliable way to know.
- Next: How prediabetes is diagnosed.
Sources
- Centers for Disease Control and Prevention. National Diabetes Statistics Report.
- National Institute of Diabetes and Digestive and Kidney Diseases. Insulin Resistance & Prediabetes.
- Tabák AG, Jokela M, Akbaraly TN, et al. Trajectories of glycaemia, insulin sensitivity, and insulin secretion before diagnosis of type 2 diabetes. Lancet. 2009;373(9682):2215–2221.
- Karadağ AS, You Y, Danarti R, Al-Khuzaei S, Chen W. Acanthosis nigricans and the metabolic syndrome. Clin Dermatol. 2018;36(1):48–53.
- American Diabetes Association Professional Practice Committee. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1).
This article is for general education and is not a substitute for advice from your own doctor or healthcare team.