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

Diabetic Eye Problems

What is diabetes?

Diabetes is a disease in which 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.

What eye problems can diabetes cause?

Over time, high blood glucose may damage the blood vessels and lenses in your eyes. This can lead to serious diabetic eye problems which can harm your vision and sometimes cause blindness. Some common diabetic eye problems include:

• Diabetic retinopathy, which is the leading cause of blindness in American adults. It affects blood vessels in the retina (the light-sensitive layer of tissue in the back of your eye). The blood vessels may swell and leak fluid into your eye. If it's not treated, it can cause serious problems such as vision loss and retinal detachment, where the retina is pulled away from its normal position at the back of your eye.
• Diabetic macular edema (DME), which happens when blood vessels in the retina leak fluid into the macula (the part of the retina needed for sharp, central vision). This usually develops in people who already have other signs of diabetic retinopathy.
• Glaucoma, a group of eye diseases that can damage the optic nerve (the bundle of nerves that connects the eye to the brain). Glaucoma from diabetes happens when the blood vessels in the front of your eye are damaged, and new blood vessels grow near the iris (the colored part of your eye). The blood vessels block the space where fluid drains from your eye. This causes fluid to build up and pressure to increase inside your eye.
• Cataract, which is the leading cause of blindness worldwide. It happens when the clear lens in the front of your eye becomes cloudy. Cataracts are common as people age. But people with diabetes are more likely to develop cataracts younger and faster than people without diabetes. Researchers think that high glucose levels cause deposits to build up in the lenses of your eyes.

Who is more likely to develop diabetic eye problems?

Anyone with diabetes can develop diabetic eye disease. But your risk of developing it is higher if you have diabetes and:

• Have had diabetes for a long time
• Don't have good control over your high blood glucose or high blood pressure
• Are pregnant
• Have high blood cholesterol
• Smoke tobacco

What are the symptoms of diabetic eye problems?

In the early stages, diabetic eye problems usually don't have any symptoms. That's why regular dilated eye exams are so important, even if you think your eyes are healthy.

You should also watch for sudden changes in your vision that could be signs of an emergency. Call your eye care professional right away if you notice any of these symptoms:

• Many new spots or dark wavy strings floating in your vision (floaters)
• Flashes of light
• A dark shadow over part of your vision, like a curtain
• Vision loss
• Eye pain or redness

Talk with your eye care professional if you have these symptoms, even if they come and go:

• Spots or dark wavy strings floating in your vision
• Blurry or wavy vision
• Vision that changes a lot
• Trouble seeing colors

How are diabetic eye problems diagnosed?

Eye care professionals do dilated eye exams to diagnose eye problems. A dilated eye exam uses eye drops to open your pupils wide so your eye care professional can look for signs of eye problems and treat them before they harm your vision. They will also test your vision and measure the pressure in your eyes.

What are the treatments for diabetic eye problems?

Treatment for diabetic eye problems depends on the problem and how serious it is. Some of the treatments include:

• Lasers to stop blood vessels from leaking
• Injections (shots) in the eye to stop new, leaky blood vessels from growing
• Surgery to remove blood and scar tissue or replace a cloudy lens
• Eye drops to lower fluid pressure in the eye

But these treatments aren't cures. Eye problems can come back. That's why your best defense against serious vision loss is to take control of your diabetes and get regular eye exams. It's also important to keep your blood pressure and cholesterol in a healthy range.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Diabetic Foot

What is diabetes?

Diabetes is a disease in which 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 can't get into your cells as quickly as usual. The glucose builds up in your blood and causes high blood sugar levels.

How does diabetes cause foot problems?

Foot problems are common in people with diabetes. They can happen over time when high blood sugar damages the nerves and blood vessels in the feet. The nerve damage, called diabetic neuropathy, can cause numbness, tingling, pain, or a loss of feeling in your feet.

If you can't feel pain, you may not know when you have a cut, blister, or ulcer (open sore) on your foot. A wound like that could get infected. The infection may not heal well because the damaged blood vessels can cause poor blood flow in your feet.

Having an infection and poor blood flow can lead to gangrene. That means the muscle, skin, and other tissues start to die. If you have gangrene or a foot ulcer that does not get better with treatment, you may need an amputation. This is a surgery to cut off your damaged toe, foot, or part of your leg. It may prevent a bad infection from spreading and could save your life.

But there's a lot you can do to prevent a foot wound from becoming a major health problem.

How can I protect my feet if I have diabetes?

The best way to protect your feet is by controlling your blood sugar levels every day. This will help keep nerve and blood vessel damage from getting worse. The next step is to keep the skin of your feet healthy.

Good foot care for people with diabetes includes:

• Checking your feet every day. Look for cuts, redness, and other changes in the skin and toenails, including warts or other spots that your shoes could rub. Make sure to check the bottoms of your feet too.
• Washing your feet every day. Use warm water and soap. Don't soak your feet because that can dry out your skin. After you dry your feet, you can use talcum powder or cornstarch between your toes. They soak up moisture that can cause infection. If you use lotion, don't apply it between your toes.
• Asking your doctor how to remove corns and calluses safely. Thick skin on your feet can rub and lead to sores. But removing it the wrong way could damage your skin. So you don't want to cut the skin or use medicated pads or liquid removers.
• Trimming your toenails straight across with a clipper. If it's hard for you to trim your own toenails, or if they're thick or curve into the skin, have a podiatrist (foot doctor) do it for you.
• Always wearing well-fitting shoes and socks or slippers to protect your feet when walking. You don't want to walk barefoot, even indoors. And be sure your shoes are smooth inside. A seam or pebble could rub your skin raw.
• Protecting your feet from heat and cold. Use sunscreen on exposed skin and don't walk barefoot at the beach. In cold weather, wear warm socks instead of warming your feet near a heater or fireplace.
• Keeping the blood flowing in your feet. Put your feet up when you're sitting. Wiggle your toes and circle your feet throughout the day. Don't wear tight socks. And get plenty of activity that's not too hard on the feet, such as walking.
• Getting your feet checked at your health care visits. Even if you haven't noticed a problem, it's good to have your health care provider look at your feet.

When should I see my health care provider about diabetic foot problems?

Serious foot problems can develop quickly. See your health care provider right away if you notice:

• A cut, blister, or bruise on your feet that doesn't start to heal in a few days
• Red, warm, or painful skin on your feet
• A callus with dried blood inside
• A foot infection that becomes black and smells bad that could be gangrene

Remember, controlling your blood sugar and caring for your feet every day are the best steps you can take to prevent serious diabetic foot problems.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Diabetic Heart Disease

What is diabetes?

Diabetes is a disease in which 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 sugar levels.

What is diabetic heart disease?

Diabetic heart disease is a term for heart disease in people who have diabetes. If you have diabetes, you are much more likely to develop heart disease or have a stroke than people who don't have diabetes. And you may start having these problems at a younger age.

Over time, the effects of high blood sugar from diabetes can include damage to the blood vessels and nerves in your heart. This damage increases your chance of developing heart diseases, including:

• Coronary artery disease (CAD). It happens slowly as a sticky material called plaque builds up in the arteries that supply your heart muscle with blood.
• Heart failure. With this condition, your heart can't pump enough oxygen-rich blood to meet the needs of your body.
• Cardiomyopathy. This is a group of diseases in which the heart muscle may become thick or stiff.

Who is more likely to develop diabetic heart disease?

Diabetes puts you at serious risk for heart disease. It also makes you more likely to develop other conditions that raise your risk even more, including:

• High blood pressure
• High blood levels of LDL "bad" cholesterol
• High triglycerides (a type of fat in your blood) with low blood levels of HDL "good" cholesterol

Your risk for heart disease is also higher if you

• Are male
• Smoke
• Have obesity
• Have too much belly fat around your waist, even though you're at a healthy weight:
  • For men, that's a waist more than 40 inches
  • For women, that's a waist more than 35 inches
• Have a family history of heart disease
• Have chronic kidney disease

What are the symptoms of diabetic heart disease?

In the early stages, heart disease usually doesn't have any symptoms. But if your heart disease worsens, you can have symptoms. Your symptoms will depend on the type of heart disease you have. They might include:

• Shortness of breath
• Fatigue
• Dizziness or fainting
• Arrhythmia (problem with the rate or rhythm of your heartbeat)
• Swollen feet and ankles
• Chest pain

It's important to know that people with diabetes may not feel chest pain. That's because diabetes can damage the nerves in your heart. If you have any symptoms that could be heart disease, talk with your health care provider.

How is diabetic heart disease diagnosed?

To find out if you have diabetic heart disease, your provider will:

• Ask about your medical history, including your symptoms and other health conditions you may have
• Ask about your family history, to find out if you have relatives who have or had heart disease
• Do a physical exam
• Likely run some tests to help understand your personal risk for heart disease, including:
  • Blood tests to check your cholesterol, triglycerides, and blood sugar levels
  • A blood-pressure check
  • Heart tests, if needed

Depending on your risk level, your provider may send you to a cardiologist (a doctor who specializes in heart diseases) for care. If you do have heart disease, treatment will depend on the type of heart disease you have.

How can I prevent diabetic heart disease?

You may be able to prevent heart disease or keep it from getting worse by working with your provider to:

• Control your blood sugar levels
• Manage other conditions you may have that can raise your risk for heart disease
• Take any medicines your provider prescribed
• Make heart-healthy habits part of your daily life
• Follow a healthy eating plan for diabetes

NIH: National Institute of Diabetes and Digestive and Kidney Diseases