How do you Diagnose Prediabetes: FBS, BSR, A1C Criteria

Prediabetes Diagnosis Criteria

Prediabetes Diagnosis Criteria are based on three simple tests: fasting blood glucose, random blood glucose, and A1C.

Prediabetes is an intermediate condition between having normal blood glucose levels and having diabetes.

It is often asymptomatic and is only diagnosed on screening tests. The only symptoms prediabetic individuals can develop are those of peripheral neuropathy manifesting as:

  • numbness
  • tingling
  • paraesthesias
  • burning, and
  • pain

in the feet and sometimes the hands (gloves and stockings neuropathy). Some people may develop symptoms of hypoglycemia and hunger after exercise or when performing household work. It is important to control overeating at this stage as it can convert to full-blown diabetes.

Compared to diabetes, prediabetes is easy to handle, can return to normal, and is usually not associated with any complications.

Before a person develops diabetes, the state of hyperinsulinemia may exist. At this stage, one should control overeating, frequently check blood glucose, and test for prediabetes and other manifestations of metabolic syndrome.

You may also like to read:

Early signs and symptoms of prediabetes

It is often asymptomatic and most people do not recognize it until they are already diabetic. However, some early signs and symptoms of prediabetes include:

  • Excessive thirst
  • Increased urination
  • Blurred vision
  • Fatigue

As mentioned, a state of hyperinsulinemia may exist. It is diagnosed when a person develops hunger, cravings, sweating, and palpitations after exertion or exercise.

This stage is very important as one can either stop the vicious cycle of hyperinsulinemia hunger and cravings (hypoglycemia) obesity and insulin resistance or hyperinsulinemia.

prediabetes vicious cycle

When insulin resistance exceeds a certain point, diabetes develops.

How to diagnose prediabetes?

The diagnosis of prediabetes is similar to that of diabetes. Symptoms of diabetes and prediabetes depend on the level of hyperglycemia.

Both diabetes and prediabetes can be present for years before symptoms may appear or the person is diagnosed.

So, if you have a family member with diabetes, you are overweight, you have metabolic syndrome, or another risk factor for developing diabetes, you should get tested for prediabetes.

You may also like to read:

Prediabetes Diagnosis Criteria: Fasting plasma glucose test:

A fasting plasma glucose test refers to a test in which blood sugar levels are checked while the person is in a fasting state (absence of food and drink intake for at least 8 hours).

It is the easiest and fastest method of checking blood glucose levels.

  • Normal: FPG levels are less than 100mg/dL (5.5 mmol/L)
  • Prediabetes: FPG levels are greater than or equal to 100mg/dL (5.5mmol/L) but less than 126 mg/dl (7.0 mmol/L)
  • Diabetes: equal to or greater than 126 mg/dl (7.0 mmol/L)

Sugar Test




FBS (Fasting Blood Sugar)< 100 mg/dl (5.5 mmol/L)100 – 125 mg/dl (5.6 – 6.9 mmol/L)=/> 126 mg/dl (7 mmol/L)
BSR (Blood Sugar random)< 140 mg/dl (7.8 mmol/L140 – 199 mg/dl (7.8 – 11 mmol/L)=/> 200 mg/dl (11.1 mmol/L)
A1C< 5.7 %5.7% – 6.4%>6.4%
You may also like to read:

Prediabetes Diagnosis Criteria: Oral Glucose Tolerance Test

For this test, do not eat for at least 8 hours before going for the test in the morning. This test involves:

  • A sample of blood is drawn
  • After that, you drink a large glass of concentrated sugar solution. This is actually 75 g of glucose dissolved in 250 ml water.
  • After 2 hours, another blood sample is drawn
  • The blood sugar levels are measured to determine diabetes.
  • The results of the test are:
    • Blood sugar less than 140 mg/dl indicates normal,
    • 140-199 mg/dl indicates prediabetes and
    • above 200mg/dl indicates diabetes.

Prediabetes Diagnosis Criteria: HbA1c:

The hbA1c is a straightforward blood test that measures an average of blood glucose levels above the past three months. It is one of the most commonly used tests to diagnose prediabetes and diabetes.

HbA1c actually measures the amount of sugar attached to hemoglobin – a protein found in red blood cells. And people having diabetes have more sugar molecules attached to hemoglobin.

The HbA1c levels are:

  • Normal: less than 5.7%
  • Prediabetes: 5.7-6.4%
  • Diabetes: greater than 6.5%

The higher your value in the prediabetic range (5.7-6.4) the greater your chance of getting type 2 diabetes.

You may also like to read:

How often you should go for an HbA1c test?

HbA1c should be repeated every 3 months in people who are 45 years or older

If your previous test results indicate prediabetes, you need to repeat the test twice every year along with regular monitoring of random and fasting sugar levels

If there are no symptoms but the test results put you in the diabetic or prediabetic range, repeat the test in the coming days to get confirmation.

If your test results confirm diabetes and you have symptoms, start managing your diabetes through medication and lifestyle changes.

Which test is better for prediabetes management?

The most reliable tool for prediabetes confirmation is HbA1c but it does not mean that you replace it with your regular testing at home.

This is because you should not miss the timely fluctuations in your glucose levels if you are careful with your prediabetes management.

People with regular fluctuations in their blood glucose levels and those with no fluctuations can have the same result in HbA1c because it represents an average over the past three months.

Regular monitoring is important to keep track of occasional highs and lows in sugar levels.

Measurement of Fasting and post-prandial blood glucose test may be a more suitable parameter to identify patients that are at a high risk of developing micro and macrovascular complications.

IGT (impaired Glucose Tolerance) as measured by Oral Glucose Tolerance Test is a more sensitive test for identifying prediabetic individuals and repetitive postprandial hyperglycemia may have greater pathophysiologic consequences than persistent hyperglycemia.

You may also like to read:

Why is the diagnosis of prediabetes important?

Diagnosis of prediabetes is important because the microvascular and macrovascular changes commonly associated with diabetes actually begin during the prediabetic stage when insulin resistance starts.

Another reason for early diagnosis is the link of prediabetes with other chronic diseases. a high cardiovascular and stroke risk among prediabetic individuals, which may be 2 to 3 times that of individuals with normal glucose values

Despite the associated disease burden, prediabetes is neglected and does not fall within the criteria of primary prevention. Therefore, adequate interventions are often not taken seriously.

Frequent screening for its diagnosis and early intervention should be the goal. Patients with prediabetes should be counseled about effective strategies

In Conclusion:

Prediabetes is an asymptomatic state of impaired blood glucose. It is usually identified on usual screening tests, especially in people at high risk of developing diseases such as those with metabolic syndrome.

Sometimes, prediabetes may present as symptoms of hyperinsulinemia or hypoglycemia which can progress to diabetes, if not timely managed.

Rarely, people with prediabetes may present with symptoms of peripheral diabetic neuropathy. These symptoms are identical to those in patients with diabetic neuropathy. These included tingling, numbness, and paraesthesias.

The three common tests used to diagnose prediabetes include FBS (Fasting blood glucose), BSR (Blood sugar random or 2 hours post-meal glucose), and A1C.

You may also like to read:

What do you think?

Written by Dr. Ahmed

I am Dr. Ahmed (MBBS; FCPS Medicine), an Internist and a practicing physician. I am in the medical field for over fifteen years working in one of the busiest hospitals and writing medical posts for over 5 years.

I love my family, my profession, my blog, nature, hiking, and simple life. Read more about me, my family, and my qualifications

Here is a link to My Facebook Page. You can also contact me by email at or at My Twitter Account
You can also contact me via WhatsApp 🙏

signs and symptom of gestational diabetes pregnancy high blood sugars during pregnancy medications for gestational diabetes meds

Gestational Diabetes Symptom and Signs

insulin side effects gestational diabetes insulin gdm once a week insulin icodec victoza and pcos best insulin for type 2 diabetes

Once a Week Insulin Icodec: A Newer Generation Insulin