Prediabetes is a condition where your blood sugar levels are higher than normal — but not yet high enough to be diagnosed as type 2 diabetes. It is also called impaired glucose tolerance. Without lifestyle changes, prediabetes often progresses to type 2 diabetes within a few years. The good news is that with the right steps, you can slow or even stop that from happening.
What Is Prediabetes?
In prediabetes, your body does not respond properly to insulin. Insulin is a hormone made by your pancreas that helps sugar move from your blood into your cells for energy. When your cells resist insulin, sugar builds up in your bloodstream instead. This is called insulin resistance.
Over time, this buildup raises your blood sugar to an unhealthy level. However, it stays just below the threshold for a full type 2 diabetes diagnosis. Think of prediabetes as an early warning signal from your body. Most people who develop type 2 diabetes pass through a stage of prediabetes first.
According to Health Canada, diabetes and its related conditions affect a growing number of Canadians every year. Catching prediabetes early gives you a real chance to protect your long-term health.
Causes of Prediabetes
Prediabetes develops when your body struggles to keep blood sugar in a healthy range. Normally, your pancreas releases enough insulin after you eat. This insulin tells your cells to absorb glucose from the food you just consumed.
When your cells stop responding well to insulin, glucose stays in your blood. Your pancreas tries to compensate by making more insulin. Eventually, it cannot keep up, and blood sugar rises. This is the core process behind both prediabetes and type 2 diabetes.
Left untreated, prediabetes can progress to type 2 diabetes. As a result, serious complications can follow — including heart disease, stroke, kidney damage, and nerve damage. That is why early action matters so much.
Prediabetes Symptoms: Why It Is Easy to Miss
One of the biggest challenges with prediabetes is that it usually has no symptoms. Most people feel completely fine. This means many Canadians are living with prediabetes and do not know it.
Because there are no obvious warning signs, prediabetes is most often caught through routine blood tests. Your family doctor may check your blood sugar as part of a regular health check-up or if you have known risk factors.
In some cases, a skin condition called acanthosis nigricans can appear. This causes dark, velvety patches of skin around the neck, armpits, or groin. However, this is not always present. Do not wait for symptoms — if you have risk factors, ask your doctor about testing.
The Importance of Early Detection
Research shows that roughly 25% of people with prediabetes will develop type 2 diabetes within 3 to 5 years. Furthermore, up to 70% may develop it over their lifetime. These are significant numbers, but they are not inevitable.
Even in the prediabetes stage — before any symptoms appear — your risk of cardiovascular complications is already elevated. Studies suggest that persistently high blood sugar at prediabetes levels can increase your risk of heart and blood vessel problems by up to 10 times compared to people with normal blood sugar. Early detection, therefore, is not just helpful. It is potentially lifesaving.
Risk Factors for Prediabetes
Prediabetes shares most of its risk factors with type 2 diabetes. Some risks are beyond your control. Others can be reduced with lifestyle changes. Understanding both categories helps you take the right steps.
Risk Factors You Cannot Change
Family history: Having a parent, sibling, or close relative with prediabetes or type 2 diabetes raises your risk.
Age: The risk increases as you get older. However, children and teenagers can also develop prediabetes, especially those who are overweight or sedentary.
Ethnicity: In Canada, Indigenous peoples, South Asian, East Asian, African, Hispanic, and Pacific Islander communities face a higher risk of type 2 diabetes and prediabetes compared to the general population.
Gestational diabetes history: Women who had diabetes during pregnancy, or who gave birth to a baby weighing over 4 kg, have a higher risk of developing prediabetes later in life.
Low birth weight: Being born weighing less than 2.5 kg can increase your risk of developing type 2 diabetes as an adult.
Risk Factors You Can Control
Excess weight: Carrying extra weight — especially around your abdomen — is one of the strongest risk factors. A waist measurement over 102 cm for men or 88 cm for women raises risk significantly, even if your overall weight seems normal.
Physical inactivity: Exercising less than once a week can increase your risk of developing type 2 diabetes by 20% to 40%. Sitting for long periods — for example, watching television for many hours — is also linked to higher obesity and diabetes risk.
High blood pressure: Blood pressure readings above 140/90 mmHg — or taking medication to control blood pressure — is a known risk factor for prediabetes.
Unhealthy cholesterol levels: Low HDL (“good”) cholesterol below 35 mg/dL, or high triglycerides above 250 mg/dL, are associated with higher prediabetes risk.
Poor diet: Eating lots of refined sugars, red meat, processed foods, and low-fibre foods increases your risk. In contrast, a diet rich in vegetables, fruit, fish, poultry, and whole grains is protective.
Polycystic ovary syndrome (PCOS): This hormonal condition disrupts normal ovulation and is linked to insulin resistance and prediabetes in women.
Metabolic syndrome: This is a cluster of metabolic problems — including high blood sugar, belly fat, high blood pressure, and abnormal cholesterol — that together raise diabetes and heart disease risk.
For more information on risk factors and prevention, visit the Mayo Clinic’s prediabetes resource page.
How Prediabetes Is Diagnosed
Your doctor will use a combination of your medical history, a physical examination, and blood tests to check for prediabetes. There are no special symptoms to report — the diagnosis relies almost entirely on lab results.
The most common tests used include a fasting blood glucose test and an oral glucose tolerance test (OGTT). A fasting blood glucose level between 6.1 and 6.9 mmol/L, or a 2-hour OGTT reading between 7.8 and 11.0 mmol/L, typically indicates prediabetes in Canada. Your doctor will interpret your results based on your full health picture.
Routine blood sugar screening is recommended for adults who are overweight and have at least one other risk factor. If you are 40 or older, your family doctor may include blood sugar testing as part of your regular check-up, even without obvious risk factors.
Preventing Type 2 Diabetes: What You Can Do
The most encouraging fact about prediabetes is that lifestyle changes genuinely work. You do not need a dramatic overhaul — small, consistent steps can make a meaningful difference.
Research shows that losing just 7% of your body weight — for example, about 5 to 7 kg for someone weighing 80 kg — can reduce your risk of developing type 2 diabetes by 58% over three years. That is a powerful result from a modest change.
Healthy Eating for Blood Sugar Control
Focus on reducing refined carbohydrates and added sugars in your diet. Choose whole grains, vegetables, legumes, and high-fibre foods instead. Fibre slows how quickly sugar enters your bloodstream, which helps keep blood sugar stable.
Limit red and processed meats, sugary drinks, and packaged snack foods. In addition, try to eat regular meals rather than skipping them — irregular eating patterns can make blood sugar harder to manage.
Physical Activity
Aim for at least 150 minutes of moderate physical activity each week. Brisk walking, cycling, swimming, or dancing all count. Even breaking up long periods of sitting — for example, standing up for five minutes every hour — can benefit your blood sugar levels.
Exercise helps your cells become more sensitive to insulin. As a result, your body can manage blood sugar more efficiently without needing as much insulin to do the job.
Managing Other Health Numbers
If you have prediabetes, keep your blood pressure below 140/90 mmHg and maintain healthy cholesterol levels. These targets help protect your heart and blood vessels, which are already at higher risk when blood sugar is elevated. Your doctor can help you set personal goals and create a management plan that works for you.
The World Health Organization’s diabetes fact sheet also outlines global guidance on prevention and healthy living strategies.
When to See a Doctor
You should speak with your family doctor about blood sugar testing if you are overweight or obese and have at least one of the following risk factors:
A close relative with diabetes or prediabetes
Belonging to a higher-risk ethnic group
A history of gestational diabetes or giving birth to a large baby
High blood pressure or heart disease
Low HDL cholesterol or high triglycerides
Polycystic ovary syndrome (PCOS)
A very sedentary lifestyle
Acanthosis nigricans (dark patches on the skin)
If you do not have a regular family doctor, a walk-in clinic can perform a blood sugar test and refer you for follow-up care. Many provincial health plans cover routine blood work, so cost should not be a barrier. Do not wait for symptoms — by the time symptoms appear, prediabetes may have already progressed.
Always speak with a qualified healthcare provider before making changes to your diet, exercise routine, or medications. This article is for informational purposes only and does not replace professional medical advice.
Frequently Asked Questions About Prediabetes
Can prediabetes be reversed?
Yes, prediabetes can often be reversed with lifestyle changes. Losing a modest amount of weight, eating a healthier diet, and becoming more physically active can bring blood sugar levels back to a normal range. Many Canadians have successfully managed prediabetes through these steps before it progressed to type 2 diabetes.
What are the warning signs of prediabetes?
Prediabetes usually has no noticeable symptoms, which is why it is so often missed. In some cases, darkened skin patches — called acanthosis nigricans — may appear around the neck or armpits. The only reliable way to detect prediabetes is through a blood sugar test ordered by your doctor or at a walk-in clinic.
What blood sugar level is considered prediabetes in Canada?
In Canada, a fasting blood glucose level between 6.1 and 6.9 mmol/L typically indicates prediabetes. A result between 7.8 and 11.0 mmol/L on a two-hour oral glucose tolerance test also suggests prediabetes. Your family doctor will interpret your results in the context of your overall health.
How quickly does prediabetes turn into type 2 diabetes?
Research suggests that about 25% of people with prediabetes will develop type 2 diabetes within 3 to 5 years without any intervention. However, with healthy lifestyle changes, many people can delay or prevent this progression entirely. Starting early gives you the best chance of protecting your long-term health.
Is prediabetes covered under provincial health plans in Canada?
Routine blood tests to screen for prediabetes are generally covered under provincial health insurance plans when ordered by a physician. Coverage for diabetes education programmes and dietitian services varies by province. Ask your family doctor or provincial health authority what resources are available to you at no cost.
What is the difference between prediabetes and type 2 diabetes?
Both prediabetes and type 2 diabetes involve higher-than-normal blood sugar caused by insulin resistance. The key difference is the degree — prediabetes means blood sugar is elevated but not yet at the level that defines diabetes. Without treatment, prediabetes frequently progresses to full type 2 diabetes over time.
Key Takeaways
Prediabetes means your blood sugar is higher than normal but not yet at the level of type 2 diabetes.
It usually has no symptoms — most people only find out through a blood test.
Up to 70% of people with prediabetes may develop type 2 diabetes over their lifetime without intervention.
Losing just 7% of your body weight can cut your diabetes risk by 58% over three years.
Key lifestyle changes include eating more fibre, reducing refined sugars, and getting at least 150 minutes of exercise per week.
Talk to your family doctor or visit a walk-in clinic if you have risk factors — blood sugar testing is simple and widely covered under provincial health plans.
Managing blood pressure and cholesterol alongside blood sugar protects your heart and overall health.
