Overview

When you have diabetes, you may have high blood sugar levels (hyperglycemia) or low blood sugar levels (hypoglycemia) from time to time. A cold, influenza (flu), or other sudden illness can cause high blood sugar levels. You will learn to recognize the symptoms and distinguish between high and low blood sugar levels. Insulin and some types of diabetes medicines can cause low blood sugar levels.

Learn how to recognize and manage high and low blood sugar levels. Then you can help avoid levels that can lead to medical emergencies, such as diabetic ketoacidosis or dehydration from high blood sugar levels or loss of consciousness from severe low blood sugar levels. Most high or low blood sugar problems can be managed at home. You just need to follow your doctor's instructions.

You can help avoid blood sugar problems by following your doctor's instructions on the use of insulin or diabetes medicines, diet, and exercise. Home blood sugar testing will help you see if your blood sugar is within your target range. If you've had very low blood sugar, you may be tempted to let your sugar level run high so that you don't have another low blood sugar problem. But it's so important to keep your blood sugar in your target range. To do this, follow your treatment plan and check your blood sugar regularly.

Sometimes a woman can get diabetes during pregnancy. This is called gestational diabetes. Blood sugar levels are checked regularly during the pregnancy to keep levels within a target range.

Children who have diabetes need their parents' help to keep their blood sugar levels in a target range and to exercise safely. Be sure that children learn the symptoms of both high and low blood sugar. Then they can tell others when they need help. There are many support groups and diabetes education centres to help parents and children understand about blood sugar, exercise, diet, and medicines.

Teens especially may have a hard time keeping their blood sugar levels in control. That's because their bodies are growing and developing. Also, they want to be with their friends and eat foods that may affect their blood sugar. Having diabetes during the teen years isn't easy. But it's an excellent age to understand the disease and its treatment. Your teen can take over some of the duties of their care.

If your blood sugar level reads too high or too low but you feel fine, you may want to recheck your sugar level or recalibrate your blood glucose meter. The problem may be with either your blood sample or the machine.

High blood sugar (hyperglycemia)

High blood sugar occurs when the sugar (glucose) level in your blood rises above your target range. Your blood sugar can rise when you eat too many calories or miss taking your medicines (insulin or pills). It can also rise when you have an infection or illness, an injury, or surgery. Even emotional stress can cause your blood sugar to rise.

High blood sugar usually happens slowly over a period of hours to days. But missing a dose of insulin can cause a quick rise in blood sugar levels. Blood sugar levels just above your target range may make you feel tired and thirsty. If your blood sugar stays higher than your target range for weeks, your body will adjust to that level. You may not have as many symptoms of high blood sugar.

Unless you don't monitor your blood sugar regularly or you don't notice the symptoms of high blood sugar, you likely will have time to treat high blood sugar so that you can prevent high blood sugar emergencies. Three things can help you prevent high blood sugar problems:

• Test your blood sugar often. This is even more important if you are sick or aren't following your normal routine. You can see when your blood sugar is above your target range. This is true even if you don't have symptoms such as increased thirst, increased urination, and fatigue. Then you can treat it early and prevent an emergency.
• Call your doctor if you often have high blood sugar levels. And call if your blood sugar level consistently stays above your target range. Your medicine may need to be adjusted or changed.
• Drink extra water or non-caffeinated, non-sugared drinks so you won't be dehydrated. If your blood sugar keeps rising, your kidneys will increase the amount of urine produced. That can make you dehydrated.

Complications of high blood sugar can cause serious problems, including coma and death. Over time, high blood sugar can damage your eyes, heart, kidneys, blood vessels, and nerves.

Low blood sugar (hypoglycemia)

Low blood sugar occurs when the sugar (glucose) level in your blood drops below what your body needs. Your blood sugar can drop quickly if you don't eat enough food or you skip meals. It can also happen if you take too much medicine (insulin or pills), exercise more than usual, or take certain medicines that lower blood sugar. Do not drink alcohol if you have problems noticing the early signs of low blood sugar.

People who lose weight or develop kidney problems may not need as much insulin or other medicines as they did before they lost the weight or had kidney problems. Their blood sugar may drop too low. Be sure to check your blood sugar often when your body goes through changes.

When your blood sugar level drops below 4.0 mmol/L, you will usually have symptoms of low blood sugar. This can happen quickly, in 10 to 15 minutes.

• If your blood sugar level drops just slightly below your target range (mild low blood sugar), you may feel tired, anxious, weak, shaky, or sweaty. And you may have a fast heart rate. If you eat something that contains sugar, these symptoms may last only a short time. If you have diabetes, you may not always notice symptoms of mild low blood sugar. This is called hypoglycemia unawareness. Your risk of this is higher if your blood sugar is well controlled and doesn't change much during the day.
• If your blood sugar level keeps dropping, your behaviour may change. You may feel more grouchy. You may become too weak or confused to eat something with sugar to raise your blood sugar level. Anytime your blood sugar drops below 4.0 mmol/L, you should act whether you have symptoms or not.
• If your blood sugar level drops very low (usually below 2.8 mmol/L), you may lose consciousness. Or you may have a seizure. If you have symptoms of severe low blood sugar, you need medical care right away.

You may have symptoms of low blood sugar if your blood sugar drops from a high level to a lower level. For example, if your blood sugar level has been higher than 17.0 mmol/L for a week or so and the level drops suddenly to 5.0 mmol/L, you may have symptoms of low blood sugar. This could happen even if your blood sugar is in the target range. But if you've had diabetes for many years, you may not have symptoms of low blood sugar until your blood sugar level is very low.

If your doctor thinks you have low blood sugar levels but you aren't having symptoms, your doctor may ask you to check your blood sugar more often. You may need to check your blood sugar in the middle of the night. Or you may need to do a 3-day test using a continuous glucose monitor.

Self-Care

Manage blood sugar levels

One of the most important skills to learn is how to manage your blood sugar level. This is true whether you have type 1 diabetes, type 2 diabetes, or gestational diabetes.

Follow your doctor's instructions on the use of insulin or diabetes medicines, diet, and exercise. They will help you avoid blood sugar problems. You'll learn to recognize the symptoms and know if they're from high or low blood sugar levels. Then you can take the right steps to bring your blood sugar back to your target levels.

People who keep their blood sugar levels under control with diet, exercise, or oral diabetes medicines are less likely to have problems with high or low blood sugar levels. Do not drink alcohol if you have problems noticing the early signs of low blood sugar.

Treat high blood sugar

If you have symptoms of high blood sugar, check your blood sugar. Your goal is to get your level back to your target range.

Here are ways you can treat high blood sugar.

• If you missed a dose of your diabetes medicine, take it now. Take only the amount of medicine that you have been prescribed. Do not take more or less medicine.
• Give yourself insulin if your doctor has prescribed it for high blood sugar.
• Test for ketones, if your doctor told you to do so. If the results of the ketone test show a moderate to large amount of ketones, call the doctor for advice.
• Wait 30 minutes after you take the extra insulin or the missed medicine. Check your blood sugar again.

If your symptoms or blood sugar levels are getting worse or have not improved after taking these steps, seek medical care right away.

Treat low blood sugar

You can treat low blood sugar by eating or drinking something that has 15 grams of carbohydrate. These should be quick-sugar foods. Check your blood sugar level again 15 minutes after having a quick-sugar food to make sure your level is getting back to your target range.

Children usually need less than 15 grams of carbohydrate. Check with your doctor or diabetes educator for the amount that is right for your child.

Here are examples of quick-sugar foods that have 15 grams of carbohydrate:

• 3 to 4 glucose tablets.
• 1 tablespoon (15 mL) of table sugar
• 1 tablespoon (15 mL) honey
• 2/3 cup (150 mL) of fruit juice or regular (not diet) soda.
• Hard candy (such as 6 Life Savers)

If you have problems with severe low blood sugar, someone else may have to give you glucagon. This is a hormone that raises blood sugar levels quickly.

When to call for help during self-care

Call a doctor if any of the following occur during self-care at home:

• Symptoms of low blood sugar, such as sweating, shakiness, extreme hunger, nausea, or dizziness.
• Symptoms of high blood sugar, such as increased thirst, increased urination, fatigue, or light-headedness.
• Symptoms occur more often or are more severe.

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