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Prediabetes or Borderline Diabetes - Causes, Risk Factors, Symptoms, Diagnosis, and Prevention

Written by
Dr. Asna Fatma
and medically reviewed by Dr. Nagaraj

Published on Sep 21, 2022 and last reviewed on Sep 30, 2022   -  5 min read


Prediabetes is a slight increase in blood sugar level that indicates progressing type 2 diabetes. Read this article to know more about it.

What Is Prediabetes?

Prediabetes, also known as borderline diabetes, is a condition where the blood sugar level is high, but it is not high enough to be diagnosed as diabetes. This occurs when the body does not produce or use insulin efficiently, which leads to excessive glucose build-up in the blood. People affected by prediabetes are highly susceptible to developing type 2 diabetes later. Over 84 million people above 20 years of age in America have prediabetes, but most of these cases are undiagnosed. In prediabetes, the body struggles to keep the blood sugar level within the normal range, and it is like a warning for the patients before they develop into full-blown type 2 diabetes.

What Causes Prediabetes?

Prediabetes is primarily caused due to insulin inefficiency in the body. The body either does not produce adequate insulin or fails to utilize it. Insulin is a hormone produced by the pancreas in our body that helps in glucose metabolism (converts glucose into energy). This insulin allows the glucose to enter the cells, where they are used to fuel the body. Without insulin, or if insulin does not work effectively, the glucose does not enter the cells and gets build-up in the blood, leading to elevated blood glucose levels (blood sugar levels). Prediabetes is an indication that the body is starting to become insulin resistant.

What Are the Risk Factors for Prediabetes?

Following are the risk factors that increase the chance of developing prediabetes:

  1. Obese or overweight individual.

  2. Individuals over 45 years of age.

  3. Have a family history of diabetes or prediabetes (when your parents, siblings, or anyone from the family have diabetes or prediabetes).

  4. Developing diabetes during pregnancy (clinically known as gestational diabetes).

  5. Individuals who have hypertension.

  6. Good cholesterol levels are low (less than 40 mg per dL), and triglyceride levels are high (more than 250 mg per dL).

  7. Women with polycystic ovary syndrome.

  8. Having a sedentary lifestyle.

  9. Smoking.

What Are the Warning Signs and Symptoms of Prediabetes?

Prediabetes typically does not have any signs or symptoms. Individuals with prediabetes will show no symptoms, or the symptoms will be very subtle. This is the reason why prediabetes has gone unnoticed for years. The only way to confirm prediabetes is by testing blood sugar levels. However, some warning signs may be seen in several cases.

  • Increased thirst (polydipsia).

  • Increased hunger (polyphagia).

  • Frequent urination (polyuria).

  • Unusual weight loss.

  • Fatigue.

  • Blurry vision.

How Is Prediabetes Diagnosed?

Some of the most common tests done to evaluate prediabetes are:

1. Plasma Glucose Fasting:

The patient fasts for at least eight hours or overnight. After that, a blood sample is collected and evaluated for glucose content.

  • Normal blood sugar range - less than 100 mg/dL.

  • Prediabetic blood sugar range - 100 to 125 mg/dL.

  • Diabetic blood sugar level - 126 mg/dL or higher.

2. Hemoglobin A1C Test:

This blood test evaluates an average blood sugar level for the past two to three months. The range for the hemoglobin A1c test is:

  • Normal range - 5.6% or less.

  • Prediabetic range - 5.7% to 6.4%.

  • Diabetic - 6.5% or above.

3. Oral Glucose Tolerance Test:

Two blood samples are collected. The first sample is taken after fasting overnight, and the second sample is collected two hours after drinking a glucose drink or something sugary. Results are evaluated based on the following parameters:

  • Normal range - A blood sugar level less than 140 mg/dL.

  • Prediabetic - A blood sugar level of 140 to 199 mg/dL.

  • Diabetic - A blood sugar level of 200 mg/dL or higher.

How to Reverse or Prevent Prediabetes?

Prediabetes can be prevented from transforming into type 2 diabetes by lifestyle modifications. Changing habits and lifestyles will delay the onset of full-blown diabetes or altogether prevent it.

  1. Diet Modification - Individuals diagnosed with prediabetes should start eating a diet that is healthy and low in carbohydrates. Avoid refined sugar and processed and fast food.

  2. Weight Loss - Losing only about 5% to 10% of the body weight can significantly prevent prediabetes.

  3. Exercise - Adapting an active lifestyle to a sedentary lifestyle can be challenging and intimidating. However, picking up an easy workout like walking or swimming for half an hour every day can be easily incorporated into routine life.

  4. Smoking - Individuals who have a habit of smoking frequently will have to quit to prevent prediabetes and other health issues.

  5. Monitoring Blood Pressure - Regularly checking blood pressure and blood cholesterol levels is crucial to check on your prediabetes and cardiovascular health.

  6. Medication - Sometimes, when the patient is at a higher risk of developing type 2 diabetes, the doctor may advise oral hypoglycemic drugs. Drugs like Metformin may be prescribed to regulate blood sugar levels.

How to Reverse Prediabetes Naturally?

Prediabetes is only a warning of insulin inefficiency in the body, and this condition can be easily reversed or prevented from turning into type 2 diabetes. In most cases, prediabetes is managed naturally without using any medications. Making a few lifestyle modifications like eating a low carbohydrate diet that is healthy, working out, taking care of mental health, maintaining a healthy sleep cycle, etc., can be very effective in reversing prediabetes naturally. These simple natural lifestyle changes can bring the blood sugar level within the normal range.

Is There a Prediabetic Diet to Prevent the Condition?

There are no strict diet plans for individuals affected by prediabetes, but careful eating habits generally help in preventing type 2 diabetes.

  • Eating a diet that is low in carbohydrates. This will include avoiding processed food, sodas, white bread, cereals, potatoes, etc.

  • Avoid taking sugar along with coffee or tea.

  • Avoid eating fast food high in calories and low in protein content.

  • Eating white meat instead of red meat.

Consulting a dietician or a diabetes expert is highly recommended to chart an efficient diet plan.


Prediabetes is a condition that is indicative of another disease. Therefore, instead of taking it as a setback and demotivating factor, it should be taken as a warning to delay or prevent type 2 diabetes from happening. Management of prediabetes is simple yet challenging because it involves numerous lifestyle changes that are meant to be followed lifelong to maintain an average blood sugar level. Therefore, prediabetes might be challenging to tackle initially but can be easily managed with cautious habits and a healthy lifestyle.

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Last reviewed at:
30 Sep 2022  -  5 min read




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