What Is Diabetes?

Diabetes is a chronic condition that prevents the body from transforming food into energy. Our bodies normally convert food into sugar, or glucose, which cells absorb and turn into the energy they need to function. For people who have diabetes, that absorption process is interrupted, causing sugar to build up in the blood. 

The buildup of sugar in the bloodstream can cause serious damage to your cardiovascular system. The shortage of sugar in the rest of your cells reduces the amount of energy available to your body, leading to possible organ damage.

Diabetes significantly increases your risk for heart disease. People with diabetes are more than three times more likely to be hospitalized with heart disease and diabetes can reduce lifespan by five to 15 years.1 In fact, up to 80% of all people with diabetes will die of either heart disease or stroke.2 People with diabetes are also more likely to be overweight and have high blood pressure and high cholesterol, all of which are strongly linked to cardiovascular disease (CVD). 

Adult men are more at risk of developing diabetes, but women are more likely to have complications.2 This is because women with diabetes are more likely to experience adverse changes that add to their risk for heart disease. They tend to have greater stores of belly fat, higher cholesterol and higher blood pressure levels. Men with diabetes experience some of the same effects but to a lesser degree. During menopause, women lose estrogen levels which is their natural protection against heart disease. 

Everyone can benefit from cutting back on sugar, but the cause of diabetes is much more complicated than that. It’s a group of diseases with a range of causes, and it’s on the rise in many parts of Canada. Recent data shows that 11.7 million Canadians live with diabetes or pre-diabetes.3  

This video explains more about diabetes and its associated risks.  

How Does Diabetes Work?

Generally, the food you eat is turned into sugar, or glucose, that your body needs. Glucose is the body’s main source of energy. Blood glucose refers to the amount of sugar in your bloodstream. 

When your blood glucose levels are too high, the pancreas (an organ located near your stomach) releases a hormone called insulin to stimulate your cells and liver to absorb glucose. This brings your blood glucose levels back to normal. 

Diabetes keeps your body either from producing enough insulin or from using its own insulin as well as it should. This causes sugars to build up in your blood. High levels of sugar in your blood can increase the buildup of fatty deposits on blood vessel walls, narrowing the walls and reducing blood flow. Over time, these deposits may harden or clog the vessels, resulting in heart disease. 

There are three main types of diabetes:

Type 1 Diabetes:

  • 10% of people with diabetes have type 1, the most severe type. 
  • It usually develops in childhood or adolescence. 
  • It is caused by a faulty immune response in which the immune system attacks and destroys part of its own pancreas. 
  • Type 1 diabetes often requires lifelong insulin treatment. 

Type 2 Diabetes:

  • 90% of people with diabetes have type 2, the most common form.5
  • It usually affects adults. 
  • The pancreas produces too little insulin or can’t use the insulin properly, which results in too much glucose building up in the blood. 
  • It can be controlled through lifestyle changes and medications. 

Gestational Diabetes Mellitus (GDM):

  • Occurs during pregnancy from hormone changes and development of the fetus.  
  • Added demand on the body to produce sufficient insulin.  
  • Increases the risk for Type 2 diabetes later in life.  
  • 30% of women with GDM will develop Type 2 diabetes within 15 years.6
  • It can be controlled through lifestyle changes and medications.  


  • “Prediabetes” is considered more of a phase of diabetes than a type.
  • It refers to blood glucose levels that are slightly out of range or higher than normal.
  • Strongly related to the risk of type 2 diabetes.
  • It can be prevented or reversed by making lifestyle changes. 

Who Is at Risk?

Type 1 diabetes is less common, and the risk for developing it usually stems from factors that are outside your control, such as environmental triggers or genetics. The following factors increase your risk of developing Type 2 diabetes and Gestational diabetes: 

Risk Factors for Type 2 Diabetes:

  • Age (being 40 years or older) 
  • Family history (having first-degree relatives with diabetes) 
  •  Being a member of a high-risk population, such as those of African, Arab, Asian, Hispanic, Indigenous or South Asian descent, low socioeconomic status 
  • Having obesity or an elevated waist circumference 
  • Having a diagnosis of prediabetes or gestational diabetes, high blood pressure, high cholesterol, obstructive sleep apnea 

Risk Factors for Gestational Diabetes:

  • Age (being 35 years or older) 
  • Ethnicity (being of Aboriginal, Hispanic, Asian, South Asian, or African descent) 
  • Giving birth to a baby weighing more than 9 pounds 
  •  Having obesity or an elevated waist circumference 
  • Having a diagnosis of polycystic ovary syndrome or acanthosis nigricans (a skin disorder) 
  • Having a previous pregnancy with gestational diabetes 
  • Having a history of using glucocorticoid medication  

To see whether you are at risk, complete this risk questionnaire


What Are the Symptoms of Diabetes?

There may be no signs or symptoms. However, possible symptoms of the onset of type 2 diabetes include:

  • Unusual thirst 
  • Frequent urination 
  • Unexpected weight gain or loss 
  • Extreme fatigue 
  • Low energy 
  • Blurry vision 
  • More frequent infections 
  • Cuts or bruises that are slow to heal 
  • Tingling and/or numbness in hands or feet 
  • Erectile difficulties 

Talk with your healthcare professional right away if you are experiencing any symptoms you believe could be associated with diabetes. 

How Is Diabetes Diagnosed?

Four blood tests can help your healthcare provider determine whether you have diabetes:  

  • Fasting Blood Glucose (FBG): FBG measures the amount of glucose in your blood while you are fasting. Fasting consists of not eating or drinking for at least eight to 10 hours before blood is drawn. Water is acceptable. 
  • Random (non-fasting) Blood Glucose: Blood is drawn at any time of day without fasting. 
  • Hemoglobin A1c (HbA1C): This non-fasting test measures the amount of glucose that has “stuck” to the red blood cells. The HbA1C is a good indicator of your average blood sugar levels over the past three months.  
  • Oral Glucose Tolerance Test (OGTT):  This test measures the body’s response to sugar.  After fasting, a blood sample is taken and you then consume a sugary drink.   Depending on the test, you will then wait either one or two hours, before another blood test is done to determine whether diabetes is present.


How Can I Reduce My Risk?

No one knows how to prevent type 1, but paying careful attention to your lifestyle choices can delay or lower your risk of developing all types of diabetes. Healthy eating, regular physical activity and weight control, as well as cholesterol and blood pressure management, can all help to slow down or avoid the development of diabetes. 

  • Follow a heart-healthy nutrition plan focusing on healthy carbohydrates.  Diabetes Canada recommends people with diabetes (or those at risk) to choose lower glycemic index (GI) foods and drinks more often to help control glucose levels. Click here to learn more about what foods increase your blood sugar and what to aim to eat more often.   
  • Enjoy regular physical activity. Getting at least 150 minutes of moderate to vigourous activity each week will help keep your blood glucose within a healthy range and promote a healthy weight.  
  • Aim to achieve your best weight. The best weight is the weight you can maintain when living the healthiest life, you are able.  

Whether you want to prevent diabetes or looking to manage it, having healthy blood glucose levels can greatly improve your overall health and well-being. If you bring your blood glucose within the target range, you are likely to have more energy, better manage your weight, and improve your blood pressure and cholesterol levels. 

Effectively managing your blood glucose will help you lower your risk for other health complications, such as cardiovascular disease, stroke, blindness, and kidney disease. If you are already diagnosed and living with diabetes, better glucose management can potentially reduce the amount of medication and/or insulin you require. 

How Is Diabetes Treated?

Treatment will vary based on the type of diabetes you have, your risk factors for other conditions, and the test results. Normally, type 2 diabetes can be treated with lifestyle changes, and these are important to controlling type 1 diabetes as well. Lifestyle changes alone can reduce your risk of developing type 2 diabetes by as much as 60% (8).

These changes in habits can also help reduce other risk factors, such as high blood pressure and cholesterol. Medications, particularly those targeted at risk factors, may still be necessary. For more information on the medical management of diabetes please refer to Diabetes Canada.  

Managing Diabetes

If you have diabetes, it is important to take your medication and live a heart-healthy lifestyle. The following are tips to help you achieve this: 

  • Take your medications as prescribed Learn about managing your diabetes by attending a diabetes education program
  • Monitor and keep track of your blood sugar based on targets discussed with your healthcare team. 
  • Eat a variety of healthy foods each day. Follow these eating tips from Diabetes Canada.  
  • Be active every day. Being physically fit significantly decreases your risk for premature death. 
  • Aim to achieve your best weight.  The best weight is the weight you can maintain when living the healthiest life, you are able. 
  • Ensure good foot health: Take care of your feet. 
  • Visit your diabetes healthcare team regularly.
    • It's natural to have questions about what food to eat. A registered dietitian can help personalize your meal plan.
    • If you have diabetes and are taking insulin, speak with your healthcare provider.
    • You may need to see an endocrinologist (a doctor who specializes in diabetes). 



1. Canadian Diabetes Association. www.diabetes.ca.

2. Vander AJ., Sherman JH., Luciano DS., : Physiologie humaine: les mécanismes du fonctionnement de l'organisme. 4th ed. Maloine E, ed. Juillet, 2004. Chenelière Mcgraw-Hill

3. Atlas of Cardiovascular Health in the Champlain Region 2011. Champlain Cardiovascular Disease Prevention Network, May 2011. http://www.ccpnetwork.ca/documents/Atlas2011FINAL.pdf

4. Stand Up to Diabetes. http://www.health.gov.on.ca/en/public/programs/diabetes/intro.

5. Champlain Diabetes Strategy. Ontario Local Health Integration Network, July 2009.

6. Lipid Clinic 2012, November 22, 2012. www.ottawaheart.ca/patients_family/lipid-clinic.htm.

7. Jaglal S, Slaughter PM. Risk factors for cardiovascular disease. In Cardiovascular Health and Services in Ontario. Toronto, Ontario, Institute for Clinical Evaluative Sciences, 1999:63-82.

8. Diabetes. University of Ottawa Heart Institute, 2012. http://www.ottawaheart.ca/heart_disease/diabetes.htm.

9. National Diabetes Education Program. http://ndep.nih.gov/am-i-at-risk/index.aspx.

10. Heart and Stroke Foundation. "Diabetes and you: manage your lifestyle. Reduce your risk." http://www.heartandstroke.com/site/c.ikIQLcMWJtE/b.5544357/k.7A75/Heart_disease__Diabetes_and_you_Manage_your_lifestyle_Reduce_your_risk.htm

11. Canadian Diabetes Association 2008 clinical practice guidelines for the prevention and management of diabetes in Canada. Canadian Journal of Diabetes. 2008; 32(1).