Prediabetes
Also known as: Impaired glucose tolerance, Impaired fasting glucose, Borderline diabetes
Prediabetes means your blood sugar levels are higher than normal but not yet high enough to be diagnosed as type 2 diabetes. It develops when the body becomes less responsive to insulin and the pancreas can no longer fully compensate. Prediabetes usually causes no symptoms, so most people do not know they have it, yet it carries an increased risk of heart disease and stroke and, without changes, a large proportion of people progress to type 2 diabetes within a decade. The encouraging news is that it is highly reversible: losing a modest amount of weight, becoming more active and improving your diet can return blood sugar to normal and cut the risk of diabetes substantially, as shown in large prevention trials.
At a Glance
- Common symptoms
- Usually no symptoms at all, Increased thirst and more frequent urination in some people, Fatigue or feeling tired after meals
- Main treatments
- Lifestyle change is the primary treatment: losing 5 to 7 percent of body weight if overweight, which markedly reduces diabetes risk, At least 150 minutes a week of moderate activity such as brisk walking, plus muscle-strengthening exercise, A diet emphasizing vegetables, whole grains, legumes, fruit, nuts and lean protein while limiting sugary drinks, refined carbohydrates and processed foods
- Category
- Metabolic · Very common; affects roughly one in three adults in many countries, most of whom are unaware
- See a doctor if
- If you are over 45 or overweight with risk factors and have never had your blood sugar checked
Symptoms
Causes
- Insulin resistance, in which muscle, fat and liver cells respond poorly to insulin
- Reduced ability of the pancreas to produce enough insulin to overcome that resistance
- Excess body fat, especially around the abdomen, which drives insulin resistance
- Physical inactivity
- Genetic predisposition
- Chronic poor sleep and high stress, which affect blood sugar regulation
Risk Factors
- Being overweight or obese, particularly with a large waist circumference
- Age 45 or older
- A family history of type 2 diabetes
- A sedentary lifestyle
- A history of gestational diabetes or polycystic ovary syndrome
- Certain ethnic backgrounds, including South Asian, Black, Hispanic, Native American and Pacific Islander ancestry
Diagnosis
- Fasting blood glucose test, with prediabetes typically defined as 100 to 125 mg/dL (5.6 to 6.9 mmol/L)
- HbA1c blood test, with a result of 5.7 to 6.4 percent indicating prediabetes
- Oral glucose tolerance test, with a 2-hour value of 140 to 199 mg/dL (7.8 to 11.0 mmol/L)
- Screening of adults over 35 to 45, and earlier for people who are overweight with additional risk factors
- Checks of blood pressure, cholesterol and weight to assess overall cardiovascular risk
Treatment
- Lifestyle change is the primary treatment: losing 5 to 7 percent of body weight if overweight, which markedly reduces diabetes risk
- At least 150 minutes a week of moderate activity such as brisk walking, plus muscle-strengthening exercise
- A diet emphasizing vegetables, whole grains, legumes, fruit, nuts and lean protein while limiting sugary drinks, refined carbohydrates and processed foods
- Structured diabetes prevention programs, which provide coaching and have strong evidence for reducing progression
- Metformin may be prescribed for people at high risk, such as those who are younger, more overweight, or have a history of gestational diabetes
- Treating high blood pressure and cholesterol to lower cardiovascular risk
- Supportive: improving sleep quality, managing stress and stopping smoking
Prevention
- Maintain a healthy weight and waist size
- Stay physically active most days of the week
- Eat a diet rich in fibre and whole foods, and limit sugary drinks and refined carbohydrates
- Get 7 to 9 hours of sleep a night
- Do not smoke
- Get screened if you are over 45 or have risk factors, so changes can start early
When to See a Doctor
- If you are over 45 or overweight with risk factors and have never had your blood sugar checked
- Increased thirst, frequent urination, unexplained weight loss or blurred vision, which may indicate diabetes
- Dark velvety skin patches on the neck or armpits
- A history of gestational diabetes, as you need regular ongoing screening
- If you have been told you have prediabetes, for a yearly check of your blood sugar and cardiovascular risk
Frequently Asked Questions
Related Conditions
Related Reading
Have questions about Prediabetes?
Ask Mother Nature AI for personalized, evidence-based guidance.
Ask about PrediabetesMedical Disclaimer: This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider.
Content reviewed against peer-reviewed medical literature and clinical guidelines. Read our editorial standards.