All about diabetes

Diabetes is a condition where people don't produce enough insulin, and/or their cells don't respond properly to insulin. Insulin is an important hormone produced by the pancreas that moves glucose, a type of sugar, into the body's cells from the blood. Once inside the body's cells, glucose is used as a source of energy. If insulin isn't available or doesn't work correctly to move glucose from the blood into cells, glucose will stay in the blood. Blood sugar levels will then increase.

In Canada, over 3 million people have diabetes, and about one-third of adults with the condition are unaware that they have it. According to the Canadian Diabetes Association, 3.7 million people in Canada will have diabetes by the year 2020.

There are 3 main kinds of diabetes: type 1 diabetes, type 2 diabetes, and gestational diabetes. Type 1 diabetes occurs when the pancreas cannot make insulin. Everyone with type 1 diabetes needs to take insulin on a daily basis. Less than 10% of all people with diabetes have type 1.

Type 2 diabetes occurs when the pancreas does not make enough insulin and/or the body does not use insulin properly. It usually occurs in adults, although in some cases, children may be affected. People with type 2 diabetes are treated with lifestyle changes (diet and exercise) and diabetes medications (either oral medications or insulin). More than 90% of all people with diabetes have type 2. Type 2 diabetes is very closely linked to body weight and obesity.

Gestational diabetes is a temporary type of diabetes that is first diagnosed during pregnancy. About 2% to 4% of pregnancies are affected by gestational diabetes. If a woman has gestational diabetes, both she and her baby have a higher risk of getting type 2 diabetes later on.

Some people with type 2 diabetes develop a condition called impaired glucose tolerance (IGT) before being diagnosed with diabetes. IGT means that the body has become less sensitive to the effects of insulin, and has to work harder to control blood glucose levels. A person with IGT has blood sugar (glucose) levels that are higher than normal but not high enough to say they have diabetes. As in type 2 diabetes, the body produces insulin, but there may be less of it, or the body does not use insulin properly.

Studies have shown that keeping blood sugar levels as close to the normal range as possible can help prevent the long-term health problems associated with diabetes, such as nerve damage, kidney disease, and blindness. Whichever type of diabetes you have, you'll need to measure your blood sugar frequently and follow a treatment plan to keep your blood sugar under control. Your doctor and pharmacist can show you how to monitor blood sugar levels. See our disease database articles on diabetes for more information.

Managing diabetes

Management is different for type 1 and type 2 diabetes.

Managing type 1 diabetes involves:

  • taking insulin on a daily basis (through injections or an insulin pump) so that your body can regulate and use sugar
  • following your doctor's advice about regulating your diet and getting appropriate exercise
  • monitoring your blood sugar levels regularly. Home blood-glucose monitors that analyze a single drop of blood are very convenient for this purpose.
  • monitoring A1C, which measures your blood sugar control over time. Your doctor will do this test every 3 months (or every 6 months if your blood sugar is consistently controlled) to see how effectively you're managing your blood sugar levels.

Your dose of insulin will be tailored to your individual needs based on several factors, including your body weight, food intake, and activity level. The goal is to try and maintain blood sugar levels as close to normal as possible.

Managing type 2 diabetes involves:

  • oral medications
  • insulin injections (in some cases)
  • dietary modifications
  • weight control and exercise
  • monitoring your blood sugar levels regularly
  • monitoring A1C

If you have type 2 diabetes, your doctor may prescribe oral medications (tablets or capsules taken by mouth). There are many kinds of oral diabetes medications. All of them work differently, but each lowers blood glucose. Ask your doctor which medication or combination of medications is most appropriate for you.

Eating an appropriate, well-balanced diet and exercising regularly is especially important in managing type 2 diabetes. Read more about this in "Nutrition and exercise to control diabetes" in this health feature.

Nutrition and exercise to control diabetes

Controlling diabetes is closely linked to diet and lifestyle.

Healthy eating

  • Smart food choices help keep blood sugar, weight, and cholesterol in better control. Focus on fewer calories, and eat less fat (especially saturated fat). Enjoy more fresh fruits, vegetables, lean meats, fish, and legumes instead.
  • The amounts of fat, carbohydrate (fruits, vegetables, breads and grains) and protein (meat, fish, milk, nuts) you eat depend on your calorie needs and goals for weight control. A healthy diet usually includes 15–20% of daily calories from protein, 20–35% from fat, and 45–60% from carbohydrates.
  • Always read the labels before trying "low fat," "light," or "no fat" foods. Some of these specially-labelled foods are "dietetic" because they're sugar free. Others are lower in calories. Some mention that they're good for people with diabetes. But many diet foods that use sugar substitutes are high in fat and calories. Words like "light" or "low" can be deceptive. Try to read the fine print!
  • Just one alcoholic beverage on an empty stomach can lower your blood sugar drastically. Sip drinks slowly and always drink alcohol with food in your stomach. Limit yourself to no more that two drinks a day and be careful when consuming brandy, port, and liqueurs, which have high sugar content.
  • Enjoy sweets in moderation: People with diabetes don't have to avoid sugar all together. You can still enjoy a cookie, a piece of cake, or chocolate every now and then. Talk to your health care professional about how to safely incorporate sweets into your diet.


  • Exercise usually lowers blood sugar. It can help insulin work more effectively and improve your health and energy.
  • Ask your doctor about the right kind of exercise for you. Get a check-up if you're starting out, and avoid overdoing it. Gradually increasing your levels of physical activity helps prevent injuries while maintaining your enthusiasm to continue exercising.
  • Check blood sugar levels before and after you exercise. This helps avoid low blood sugar. Monitoring your blood sugar can help determine how different types of activities affect sugar levels.
  • Try walking, swimming, and light weight-lifting exercises for physical activity.

Monitoring blood glucose levels

The Canadian Diabetes Association (CDA) recommends that people with diabetes who are using insulin more than once a day should self-monitor their blood glucose levels at least 3 times a day. The CDA also recommends that people with type 2 diabetes who use insulin once a day should test their blood glucose levels once a day at different times of day. People with type 2 diabetes who are not using insulin should speak to their physician or primary health care provider about how often they should test. The frequency of monitoring depends on your treatments and how well your blood sugar is controlled.

A blood glucose meter is used to test blood glucose at home and to determine whether blood glucose levels are in the target range. Meters can be obtained at most pharmacies. Testing glucose levels helps put the person with diabetes in control and be more active in managing their condition. Using blood glucose meters to determine the effects of certain foods on blood glucose levels can also help a person with diabetes to choose appropriate foods more carefully.

A person with diabetes should talk with their diabetes educator or pharmacist about which model of glucose meter is appropriate for them. Anyone using a glucose meter should receive proper training so that they can test their blood glucose levels properly.

Ask a diabetes educator about:

  • the size of the drop of blood needed
  • the type of blood glucose strips to use
  • how to check if the meter is accurate (the meter should be checked at least once a year)
  • how to code the meter
  • how to clean the meter

If a person with diabetes experiences symptoms of hypoglycemia (i.e., low blood glucose), they should check their blood glucose immediately. If a meter is not immediately available, the symptoms should still be treated with the following guidelines:

  1. Eat or drink a fast-acting carbohydrate (15 g):
    • 3 to 5 glucose tablets (the exact amount will depend on the glucose content per tablet of the brand you have; check to make sure you are aware of this amount and take enough to make up 15 g of glucose)
    • ¾ cup (175 mL) of orange juice or regular soft drink
    • 6 Life Savers®
    • 1 tablespoon (15 mL) of honey
    • 3 teaspoons (15 mL) or 3 packets of table sugar dissolved in water
  2. Wait 15 minutes, then check blood glucose again. If it is still low, treat again (repeat step 1).
  3. Once the hypoglycemia has been reversed, if the next meal is more than one hour away, or if the person is going to be active, they should eat a snack, such as a half-sandwich or cheese and unsalted crackers (something with 15 g of carbohydrate and a protein source).

Certain people at risk of hypoglycemia may be advised by their doctor to carry a prefilled 1 mg glucagon injection and make it readily available for emergency situations. This medication is intended to increase blood glucose levels rapidly.

Do-it-yourself tests for ketones are useful during times of illness. Ketones are potentially dangerous acids that build up in your blood when you lack insulin. Ketone buildup is much more common if you have type 1 diabetes. Talk to your doctor or primary health care provider about how to test for ketones.