A report that says "borderline sugar", or a glycated haemoglobin (HbA1c) a little above normal, can feel like a non-event: you feel fine, and nobody has prescribed anything. It is actually the most useful result you can get, because it arrives while there is still time to change the course.
For what diabetes is and how it is diagnosed and treated, read our diabetes guide covering symptoms, tests and treatment.
The numbers, differences between Indian and American cut-offs, and steps tested in Indians are explained below. If your result is already in the diabetes range, or you have symptoms, see a doctor rather than relying on this page.
What prediabetes means
Prediabetes is a state in which blood glucose is higher than normal but not high enough to diagnose diabetes. The Indian Council of Medical Research (ICMR) and the World Health Organization (WHO) describe two forms, and many people have both:
- Impaired fasting glucose: sugar is too high after an overnight fast, usually because the liver releases too much glucose overnight.
- Impaired glucose tolerance: sugar is too high 2 hours after a standard glucose drink, because the body struggles to handle a carbohydrate load.
The American Diabetes Association (ADA) also counts an HbA1c between 5.7% and 6.4%. HbA1c reflects your average sugar over about two to three months.
Prediabetes is common in India. The national Indian Council of Medical Research–India Diabetes (ICMR-INDIAB) study estimated it at 15.3% of adults, about 136 million people in 2021, more than the number with diabetes. It is a high-risk state, not "mild diabetes", and it is not harmless: ICMR notes that some complications start to appear at this stage, and the risk of heart disease is already higher.
Prediabetes range: the numbers and why guidelines differ
All of these are laboratory tests. A home glucometer reading cannot place you in a range.
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| Fasting plasma glucose | Below 100 mg/dL (ADA); below 110 mg/dL (WHO and ICMR) | 100–125 mg/dL (ADA); 110–125 mg/dL (WHO and ICMR) | 126 mg/dL or higher |
| 2-hour glucose tolerance test (75 g) | Below 140 mg/dL | 140–199 mg/dL | 200 mg/dL or higher |
| HbA1c | Below 5.7% | 5.7–6.4% | 6.5% or higher |
The fasting cut-off is a real guideline difference. ADA starts prediabetes at 100 mg/dL; WHO and ICMR start at 110 mg/dL. A fasting sugar of 105 mg/dL is prediabetes by one and normal by the other. In practice, treat any fasting value from 100 mg/dL up as a reason to act on lifestyle and retest, because risk rises steadily across the range rather than switching on at a line.
The tests also catch different people. Many Indians have a normal fasting sugar but an abnormal 2-hour value, so a fasting test alone can miss prediabetes. If your fasting sugar is normal but you have strong risk factors, ask your doctor whether an oral glucose tolerance test makes sense. HbA1c can mislead in anaemia, which is common in Indian women, and with some haemoglobin variants.
Signs of prediabetes: usually none
Most people with prediabetes feel completely well. It is found on a blood test, not by symptoms. A few physical clues point to insulin resistance, the problem that often sits underneath it:
- Dark, velvety patches on the back of the neck, armpits or groin, called acanthosis nigricans. Read our guide to dark patches on the neck.
- Weight carried around the waist, even with a normal body mass index (BMI).
- Irregular periods with polycystic ovary syndrome (PCOS).
If you already have thirst, frequent urination or weight loss, your sugar may be beyond prediabetes. Our guide to diabetes symptoms and early signs explains what to look for.
Who is at risk: family history, waist and more
ICMR's 2018 guideline recommends testing everyone over 30, and earlier for people with any of these risk factors:
- A parent, brother or sister with diabetes, which is the strongest everyday clue.
- A BMI of 23 or more, or a waist over 90 cm in men or 80 cm in women.
- Blood pressure of 130/80 mmHg or higher, or treatment for it.
- Abnormal cholesterol or triglycerides.
- Little physical activity.
- Gestational diabetes in a past pregnancy, or a baby born weighing more than 3.5 kg.
- Heart disease or stroke.
- PCOS or acanthosis nigricans.
The Research Society for the Study of Diabetes in India (RSSDI) goes further and suggests a yearly diabetes-risk check from age 25.
Why family history matters so much
Diabetes runs in families through shared genes and shared kitchens. You cannot change the first, but the second is often where the most change is possible. It is a reason to test early and often, not a guarantee that you will develop diabetes.
Does prediabetes always turn into diabetes?
No, but in Indians the risk is high. In the Indian Diabetes Prevention Programme, a trial in Chennai of adults with impaired glucose tolerance, 55.0% of those given no special help had developed diabetes within three years. ICMR notes that Indians tend to progress quickly from prediabetes to diabetes.
The same trial shows the other side. Some people's sugar returns to normal, and the right steps lowered the risk for the whole group. "Reversal" is the word people search for; doctors usually say that sugar has returned to the normal range. It can rise again if habits slip, which is why retesting continues.
Prevention of diabetes: what actually works
Two large trials are the backbone of prevention advice. In the US Diabetes Prevention Program, an intensive lifestyle programme cut the risk of type 2 diabetes by 58% over about three years, compared with 31% for metformin. Its goals were losing at least 7% of body weight and 150 minutes a week of moderate activity such as brisk walking. In the Indian Diabetes Prevention Programme, simpler lifestyle advice cut the risk by 28.5%, and metformin by 26.4%. Combining the two added no extra benefit.
Food
You do not need a special diet. Shift the proportions of the food you already eat: half the plate vegetables, a quarter dal, paneer, egg, fish or chicken, and a quarter roti, rice or millet. Cut added sugar, including gud and honey, and sugary drinks, and choose whole fruit over juice. Our Indian diabetes diet chart shows full day plans, and the same plate works for prediabetes.
Movement
Aim for at least 150 minutes a week of brisk walking or similar activity, such as 30 minutes on five days, plus muscle-strengthening work twice a week. A 10–15 minute walk after your largest meal is an easy place to start.
Weight, if it applies to you
ADA advises people with prediabetes and excess weight to aim for a 5–7% weight loss, which is 4–5 kg for someone weighing 70 kg. Weight loss is not the target for everyone; many Indians develop prediabetes at a normal BMI, and for them movement, waist size and food quality matter more than the scale.
Sleep and tobacco
Short or poor sleep and smoking both worsen insulin resistance. Treating snoring with breathing pauses, which can be sleep apnoea, and stopping tobacco are part of prevention.
Medicine, only if your doctor advises it
ICMR says metformin may be considered when lifestyle alone is not enough, especially with both impaired fasting glucose and impaired glucose tolerance. ADA suggests it for higher-risk groups such as those with a BMI of 35 or more or past gestational diabetes. It is a doctor's decision, not a supplement to start yourself. Our guide to diabetes medicines explains how metformin works.
How often to retest
ICMR and ADA both advise repeating a sugar test at least once a year if you have prediabetes. ICMR suggests every three years if your result is normal. Ask your doctor to check blood pressure, cholesterol and weight at the same visits, because they share the same root causes. If you are planning a pregnancy, test before you conceive.
When to see a doctor
Our diabetes guide has the full list of warning signs.
Emergency: get help now
- Vomiting, stomach pain, deep or fast breathing, fruity breath, confusion or marked drowsiness.
Prompt review: within a few days
- You have thirst, frequent urination or unexplained weight loss along with a prediabetes or higher result.
- You are pregnant and have been told your sugar is high.
Routine review
- You have a prediabetes result and want a plan, including whether a glucose tolerance test or metformin is right for you.
- A year has passed since your last test.
How Disha can help
Disha is an AI health coach that chats and calls in Hindi, English and Hinglish. After an onboarding call of about 15–20 minutes, conducted by Disha itself, it can help you build the plate, walking and sleep habits that prevention trials tested, adjusted to your own kitchen and routine, and keep them going week after week. Disha does not diagnose, prescribe or provide emergency care, and it does not replace your doctor. Read how Disha coaching works.
This is not medical advice. This page is general information for adults. Only a doctor can interpret your results alongside your history. If you are pregnant, have symptoms, or take any medicine for sugar, blood pressure or cholesterol, agree changes with your doctor. In an emergency, call 112.
Frequently asked questions
What is pre diabetes, and is it the same as borderline sugar?
Yes, "borderline sugar" usually means prediabetes: blood glucose above normal but below the diabetes range. It is diagnosed with a laboratory HbA1c of 5.7 to 6.4%, a fasting glucose of 100 to 125 mg/dL, or a 2-hour glucose tolerance result of 140 to 199 mg/dL. It needs action and yearly retesting, not reassurance.
Can prediabetes be reversed?
Often, yes. Many people's sugar returns to the normal range with sustained changes in food, movement and, where relevant, weight. In Indian and American trials, lifestyle programmes cut the risk of progressing to diabetes by 28% to 58%. It is not a one-time fix: sugar can rise again if habits slip, so keep testing yearly.
What is a normal fasting sugar level?
ADA treats a fasting plasma glucose below 100 mg/dL as normal, while WHO and ICMR use below 110 mg/dL. Values from 100 or 110 up to 125 mg/dL are prediabetes, and 126 mg/dL or more on repeat testing is diabetes. A laboratory sample after at least 8 hours without food is what counts, not a home meter.
Does prediabetes have symptoms?
Usually not, which is why testing matters. Some people have signs of insulin resistance, such as dark velvety skin on the neck or armpits, weight around the waist or irregular periods with PCOS. Thirst, frequent urination or weight loss suggest your sugar may already be higher, so see a doctor rather than waiting for the next routine test.
How long does it take to bring prediabetes back to normal?
There is no fixed timeline. HbA1c reflects about two to three months of sugar, so retesting after three months of steady change gives a fair picture. Some people see a change within that time; others take longer or need medicine. Measure progress by sustained habits and the next laboratory test, not by single home readings.
Do I need medicine for prediabetes?
Most people start with lifestyle change alone. ICMR says metformin may be considered when lifestyle is not enough, especially if both fasting and post-glucose values are high, and ADA suggests it for higher-risk groups such as people with a BMI of 35 or more or past gestational diabetes. Only your doctor should decide this.
I am thin. Can I still have prediabetes?
Yes. Many Indians develop prediabetes and diabetes at a normal BMI, often with fat stored around the waist and organs rather than visibly. Family history, low activity, past gestational diabetes and PCOS matter too. If you have any of these, test from your 20s or 30s, whatever your weight.
Sources
- American Diabetes Association Professional Practice Committee. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026. 2026. Supports: prediabetes criteria of HbA1c 5.7–6.4%, fasting glucose 100–125 mg/dL and 2-hour glucose 140–199 mg/dL; risk rising continuously across the range; yearly testing in prediabetes; acanthosis nigricans and PCOS as signs of insulin resistance.
- American Diabetes Association Professional Practice Committee. 3. Prevention or Delay of Diabetes and Associated Comorbidities: Standards of Care in Diabetes—2026. 2026. Supports: 5–7% weight loss and at least 150 minutes a week of moderate activity; at least annual monitoring; metformin for higher-risk groups such as BMI 35 or more and past gestational diabetes; summary of the Indian Diabetes Prevention Programme.
- Indian Council of Medical Research. ICMR Guidelines for Management of Type 2 Diabetes. 2018. Supports: impaired fasting glucose and impaired glucose tolerance; WHO and ADA fasting cut-offs; screening over 30 and earlier with risk factors; retesting yearly in prediabetes and every three years if normal; metformin when lifestyle is not enough, especially with combined impaired fasting glucose and impaired glucose tolerance; rapid progression in Indians; complications looked for even at prediabetes.
- Ramachandran A, Snehalatha C, Mary S, et al. The Indian Diabetes Prevention Programme shows that lifestyle modification and metformin prevent type 2 diabetes in Asian Indian subjects with impaired glucose tolerance (IDPP-1). Diabetologia, 2006. Supports: 55.0% three-year incidence without intervention; 28.5% risk reduction with lifestyle change and 26.4% with metformin; no added benefit from combining them.
- Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. New England Journal of Medicine, 2002. Supports: 58% risk reduction with intensive lifestyle change and 31% with metformin; 7% weight-loss and 150-minute activity goals.
- Anjana RM, Unnikrishnan R, Deepa M, et al. Metabolic non-communicable disease health report of India: the ICMR-INDIAB national cross-sectional study. Lancet Diabetes and Endocrinology, 2023. Supports: prediabetes prevalence of 15.3% and about 136 million adults in 2021.
- Research Society for the Study of Diabetes in India. RSSDI Clinical Practice Recommendations for the Management of Type 2 Diabetes Mellitus 2022. 2022. Supports: yearly diabetes-risk evaluation from age 25 in India and the higher sensitivity of the oral glucose tolerance test in Indians.
Related reads
- Diabetes: symptoms, tests, treatment and Indian food: the full overview of diagnosis, treatment and red flags.
- Diabetes symptoms and early signs: what to watch for if your sugar may be higher.
- Indian diabetes diet chart: the plate and day plans, which work for prediabetes too.
- Dark patches on the neck and insulin resistance: a skin sign that is a reason to test.
- All diabetes articles: every Disha guide on diabetes in one place.
- BMI calculator with Indian cut-offs: one screening measure that does not capture waist or individual health.
