Knowledge Center

Blood Glucose

What is blood glucose?

Blood glucose, or blood sugar, is the main sugar found in your blood. It is your body’s primary source of energy. It comes from the food you eat. Your body breaks down most of that food into glucose and releases it into your bloodstream. When your blood glucose goes up, it signals your pancreas to release insulin. Insulin is a hormone that helps the glucose get into your cells to be used for energy.What is diabetes?

Diabetes is a disease in which your blood glucose levels are too high. When you have diabetes, your body doesn’t make enough insulin, can’t use it as well as it should, or both. Too much glucose stays in your blood and doesn’t reach your cells. Over time, having too much glucose in your blood can cause serious health problems (diabetes complications). So if you have diabetes, it’s important to keep your blood glucose levels within your target range.What are blood glucose targets?

If you have diabetes, your blood glucose target is the range you try to reach as much as possible. The typical targets are:

• Before a meal: 80 to 130 mg/dL
• Two hours after the start of a meal: Less than 180 mg/dL

Your blood glucose targets may be different, depending on your age, any additional health problems you have, and other factors. Talk with your health care team about the best target range for you.When and how should I check my blood glucose?

If you have diabetes, you’ll likely need to check your blood glucose every day to make sure that your blood glucose numbers are in your target range. Some people may need to check their blood glucose several times a day. Ask your health care team how often you need to check it.

The most common way to check your blood glucose level at home is with a blood glucose meter. A blood glucose meter measures the amount of glucose in a small sample of blood, usually from your fingertip.

Continuous glucose monitoring (CGM) is another way to check your glucose levels. Most CGM systems use a tiny sensor that is inserted under your skin. The sensor measures your glucose level every few minutes. It can show changes in your glucose level throughout the day and night. A CGM system is especially useful for people who take insulin and have problems with low blood glucose.

Your provider will also check your blood glucose with a blood test called an A1C. It checks your average blood glucose level over the past three months. People with diabetes usually have an A1C test at least twice a year. But you may need the test more often if you aren’t meeting your diabetes treatment goals.What happens if my blood glucose level becomes too high?

High blood glucose is called hyperglycemia. Symptoms that your blood glucose levels may be too high include:

• Feeling thirsty
• Feeling tired or weak
• Headaches
• Urinating (peeing) often
• Blurred vision

If you often have high blood glucose levels or symptoms of high blood glucose, talk with your health care team. You may need a change in your diabetes meal plan, physical activity plan, or diabetes medicines.

High blood glucose may also be caused by other conditions that can affect insulin or glucose levels in your blood. These conditions include problems with your pancreas or adrenal glands.What happens if my blood glucose level becomes low for me?

Hypoglycemia, also called low blood glucose, happens when your blood glucose level drops below what is healthy for you. For many people with diabetes, this means a blood glucose reading lower than 70 mg/dL. Your number might be different, so check with your health care team to find out what blood glucose level is low for you.

Symptoms of low blood glucose tend to come on quickly. The symptoms can be different for everyone, but they may include:

• Shaking
• Sweating
• Nervousness or anxiety
• Irritability or confusion
• Dizziness
• Hunger

Low blood glucose levels can be common in people with type 1 diabetes and people with type 2 diabetes who take certain diabetes medicines. If you think you may have low blood glucose, check your level, even if you don’t have symptoms. Low blood glucose can be dangerous and should be treated as soon as possible.

Although it’s rare, you can still get low blood glucose without having diabetes. The causes can include conditions such as liver disease, kidney disease, and hormone deficiencies (lack of certain hormones). Some medicines, such as certain heart medicines and antibiotics, can also cause it. See your provider to find out the cause of your low blood glucose and how to treat it.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Diabetic Diet

What is diabetes?

If you have diabetes, your blood glucose, or blood sugar, levels are too high. Glucose comes from foods you eat. The cells of your body need glucose for energy. A hormone called insulin helps the glucose get into your cells.

With type 1 diabetes, your body doesn’t make insulin. With type 2 diabetes, your body doesn’t make or use insulin well. Without enough insulin, glucose builds up in your blood and causes high blood glucose levels.

Prediabetes means that your blood glucose levels are higher than normal but not high enough to be called diabetes. If you have prediabetes, you are more likely to develop type 2 diabetes.How do the foods I eat affect my blood glucose levels?

The glucose in your blood comes from certain foods called carbohydrates, or “carbs.” Foods that are high in carbs include candy and sweets, sodas, breads, tortillas, and white rice. The more carbs you eat, the higher your blood glucose level will be.

Whether you have type 1 or type 2 diabetes, making the right food choices is an important way to keep your blood glucose at a level that is healthy for you. When you control your blood glucose, you lower your chance of having serious health problems from diabetes, such as vision loss and heart problems.

And if you have prediabetes or are at risk for diabetes, eating foods that keep your blood glucose levels healthy may help prevent type 2 diabetes later on.What’s the best diet for diabetes?

There isn’t a specific diet or meal plan that works for everybody. Your health care provider may have you see a registered dietician (RD) or a diabetes educator who can help design the best eating plan for you. The plan will consider:

• Any medicines that you take
• Your weight
• Any other health conditions you have
• Your lifestyle and tastes
• Your goals

All eating plans for diabetes have a few things in common, including eating the right foods in the right amounts at the right times.What foods should I eat if I have diabetes?

Eating the right foods for diabetes means eating a variety of healthy foods from all the food groups:

• Fruits and vegetables
• Whole grains, such as whole wheat, brown rice, barley, quinoa, and oats
• Proteins, such as lean meats, chicken, turkey, fish, eggs, nuts, beans, lentils, and tofu
• Nonfat or low-fat dairy, such as milk, yogurt, and cheese

What foods should I limit to control my blood glucose?

To keep your blood glucose under control, you may need to cut back on certain foods and drinks. This doesn’t mean that you can never enjoy them. But you will need to have them less often or in smaller amounts.

• High-carb foods and drinks, such as:
  • Sugary foods, such as candy, cookies, cake, ice cream, sweetened cereals, and canned fruits with added sugar
  • Drinks with added sugars, such as juice, regular soda, and regular sports or energy drinks
  • White rice, tortillas, breads and pasta – especially those made with white flour
  • Starchy vegetables, such as white potatoes, corn, and peas
• Fried foods and other foods high in saturated trans fats.
• Foods high in sodium (salt).
• Alcohol. If you do drink, you should drink moderately. This means no more than one standard drink a day if you’re a woman or two standard drinks a day if you’re a man.

What else do I need to know about diabetic diets?

If you have diabetes, it’s important to eat the right amount of food every day. Your eating plan will include how much to eat, so that you get the right amount of carbs in each meal or snack. You’ll learn how to count carbs and measure your food.

Eating at the right times is also important. You will want to plan for regular, balanced meals to avoid blood glucose levels that are too high or too low for you. Eating about the same amount of carbs at each meal can be helpful.

Your eating plan will also teach you how to stick with your plan at home and when you eat out.

Eating healthy to control your blood glucose does take some effort. But the reward is a chance to live your healthiest life with diabetes.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases