What is hyperglycemia

Hyperglycemia is the technical term for high blood glucose (blood sugar). High blood sugar (hyperglycemia) affects people who have diabetes. High blood glucose happens when the body has too little insulin or when the body can’t use insulin properly ¹⁾.

Several factors can contribute to hyperglycemia in people with diabetes, including food and physical activity choices, illness, nondiabetes medications, or skipping or not taking enough glucose-lowering medication.

It’s important to treat hyperglycemia, because if left untreated, hyperglycemia can become severe and lead to serious complications requiring emergency care, such as a diabetic coma. In the long term, persistent hyperglycemia, even if not severe, can lead to complications affecting your eyes, kidneys, nerves and heart.

Table 1. Fasting blood glucose – this test measures the level of glucose in the blood after an 8-12 hour fast.

Hyperglycemia Causes

During digestion, your body breaks down carbohydrates from foods — such as bread, rice and pasta — into various sugar molecules. One of these sugar molecules is glucose, a main energy source for your body. Glucose is absorbed directly into your bloodstream after you eat, but it can’t enter the cells of most of your tissues without the help of insulin — a hormone secreted by your pancreas.

When the level of glucose in your blood rises, it signals your pancreas to release insulin. The insulin, in turn, unlocks your cells so that glucose can enter and provide the fuel your cells need to function properly. Any extra glucose is stored in your liver and muscles in the form of glycogen.

This process lowers the amount of glucose in your bloodstream and prevents it from reaching dangerously high levels. As your blood sugar level returns to normal, so does the secretion of insulin from your pancreas.

Diabetes drastically diminishes the effects of insulin on your body, either because your pancreas is unable to produce enough insulin (type 1 diabetes) or because your body is resistant to the effects of insulin or doesn’t produce enough insulin to maintain a normal glucose level (type 2 diabetes). As a result, glucose tends to build up in your bloodstream (hyperglycemia) and may reach dangerously high levels if not treated properly. Insulin or other drugs are used to lower blood sugar levels.

A number of things can cause hyperglycemia:

• If you have type 1 diabetes, you may not have given yourself enough insulin.
• If you have type 2 diabetes, your body may have enough insulin, but it is not as effective as it should be or you may not take enough other blood glucose-lowering medications.
• You ate more than planned or exercised less than planned.
• You have stress from an illness, such as a cold or flu.
• You have other stress, such as family conflicts or school or dating problems.
• You may have experienced the dawn phenomenon (a surge of hormones that the body produces daily around 4:00 a.m. to 5:00 a.m.).
• Insulin pump or infusion set malfunction
• Food intake that has not been covered adequately by insulin
• Decreased physical activity
• Infection
• Injury or having surgery
• Severe physical or emotional stress or workplace challenges

Illness or stress can trigger hyperglycemia because hormones produced to combat illness or stress [cortisol] can also cause your blood sugar to rise. Even people who don’t have diabetes may develop hyperglycemia during severe illness. But people with diabetes may need to take extra diabetes medication to keep blood glucose near normal during illness or stress.

Complications of Hyperglycemia

Long-term complications of Hyperglycemia

Untreated hyperglycemia can cause long-term complications. These include:

• Cardiovascular disease
• Nerve damage (neuropathy)
• Kidney damage (diabetic nephropathy) or kidney failure
• Damage to the blood vessels of the retina (diabetic retinopathy), potentially leading to blindness
• Clouding of the normally clear lens of your eye (cataract)
• Feet problems caused by damaged nerves or poor blood flow that can lead to serious infections, and in some severe cases, amputation
• Bone and joint problems
• Skin problems, including bacterial infections, fungal infections and nonhealing wounds
• Teeth and gum infections

Emergency complications of Hyperglycemia

If blood sugar rises high enough or for a prolonged period of time, it can lead to two serious conditions.

Diabetic ketoacidosis. Diabetic ketoacidosis develops when you don’t have enough insulin in your body. When this happens, sugar (glucose) can’t enter your cells for energy. Your blood sugar level rises, and your body begins to break down fat for energy.

This process produces toxic acids known as ketones. Excess ketones accumulate in the blood and eventually “spill over” into the urine. Left untreated, diabetic ketoacidosis can lead to a diabetic coma and be life-threatening.

Hyperglycemic hyperosmolar syndrome. This condition occurs when people produce insulin, but it doesn’t work properly. Blood glucose levels may become very high — greater than 600 mg/dL (33 mmol/L). Because insulin is present but not working properly, the body can’t use either glucose or fat for energy.

Glucose is then spilled into the urine, causing increased urination. Left untreated, diabetic hyperglycemic hyperosmolar syndrome can lead to life-threatening dehydration and a coma. Prompt medical care is essential.

Prevention of Hyperglycemia

The following suggestions can help keep your blood sugar within your target range:

• Follow your diabetes meal plan. If you take insulin or oral diabetes medication, it’s important that you be consistent about the amount and timing of your meals and snacks. The food you eat must be in balance with the insulin working in your body.
• Monitor your blood sugar. Depending on your treatment plan, you may check and record your blood sugar level several times a week or several times a day. Careful monitoring is the only way to make sure that your blood sugar level remains within your target range. Note when your glucose readings are above or below your goal range.
• Take your medication as prescribed by your health care provider.
• Adjust your medication if you change your physical activity. The adjustment depends on the blood sugar test results and on the type and length of the activity.

Medical IDs

Many people with diabetes, particularly those who use insulin, should have a medical ID with them at all times.

In the event of a severe hypoglycemic episode, a car accident, or other emergency, the medical ID can provide critical information about the person’s health status, such as the fact that they have diabetes, whether or not they use insulin, whether they have any allergies, etc. Emergency medical personnel are trained to look for a medical ID when they are caring for someone who can’t speak for themselves.

Medical IDs are usually worn as a bracelet or a necklace. Traditional IDs are etched with basic, key health information about the person, and some IDs now include compact USB drives that can carry a person’s full medical record for use in an emergency.

Signs and symptoms of hyperglycemia

Hyperglycemia doesn’t cause symptoms until glucose values are significantly elevated — above 200 milligrams per deciliter (200 mg/dL), or 11 millimoles per liter (11 mmol/L). Symptoms of hyperglycemia develop slowly over several days or weeks. The longer blood sugar levels stay high, the more serious the symptoms become. However, some people who’ve had type 2 diabetes for a long time may not show any symptoms despite elevated blood sugars.

The signs and symptoms of high blood sugar include the following:

• High blood glucose
• High levels of sugar in the urine
• Frequent urination
• Increased thirst

Early signs and symptoms of high blood sugar

Recognizing early symptoms of hyperglycemia can help you treat the condition promptly. Watch for:

• Frequent urination
• Increased thirst
• Blurred vision
• Fatigue
• Headache

Part of managing your diabetes is checking your blood glucose often. Ask your doctor how often you should check and what your blood glucose levels should be. Checking your blood and then treating high blood glucose early will help you avoid problems associated with hyperglycemia.

Later signs and symptoms of high blood sugar

If hyperglycemia goes untreated, it can cause toxic acids (ketones) to build up in your blood and urine (ketoacidosis). Signs and symptoms include:

• Fruity-smelling breath
• Nausea and vomiting
• Shortness of breath
• Dry mouth
• Weakness
• Confusion
• Coma
• Abdominal pain

Call your local emergency number for emergency medical assistance if:

• You’re sick and can’t keep any food or fluids down, and
• Your blood glucose levels are persistently above 240 mg/dL (13 mmol/L) and you have ketones in your urine.

What if Hyperglycemia Goes Untreated?

Hyperglycemia can be a serious problem if you don’t treat it, so it’s important to treat as soon as you detect it. If you fail to treat hyperglycemia, a condition called ketoacidosis (diabetic coma) could occur. Ketoacidosis develops when your body doesn’t have enough insulin. Without insulin, your body can’t use glucose for fuel, so your body breaks down fats to use for energy.

When your body breaks down fats, waste products called ketones are produced. Your body cannot tolerate large amounts of ketones and will try to get rid of them through the urine. Unfortunately, the body cannot release all the ketones and they build up in your blood, which can lead to ketoacidosis.

Ketoacidosis is life-threatening and needs immediate treatment. Symptoms include:

• Shortness of breath
• Breath that smells fruity
• Nausea and vomiting
• Very dry mouth

Talk to your doctor about how to handle this condition.

How To Diagnose Hyperglycemia

Your doctor sets your target blood sugar range. For many people who have diabetes, doctors generally recommends target blood sugar levels that are:

• Between 80 and 120 mg/dL (4 and 7 mmol/L) for people age 59 and younger who have no other underlying medical conditions
• Between 100 and 140 mg/dL (6 and 8 mmol/L) for people age 60 and older, those who have other medical conditions, such as heart, lung or kidney disease, or those who have a history of low blood sugar (hypoglycemia) or who have difficulty recognizing the symptoms of hypoglycemia

Your target blood sugar range may differ, especially if you’re pregnant or you develop diabetes complications. Your target blood sugar range may change as you get older, too. Sometimes, reaching your target blood sugar range is a challenge.

Home blood sugar monitoring

Routine blood sugar monitoring with a blood glucose meter is the best way to be sure that your treatment plan is keeping your blood sugar within your goal range. Check your blood sugar as often as your doctor recommends.

If you have any signs or symptoms of severe hyperglycemia — even if they’re subtle — check your blood sugar level. If your blood sugar level is 240 mg/dL (13 mmol/L) or above, use an over-the-counter urine ketones test kit. If the urine test is positive, your body may have started making the changes that can lead to diabetic ketoacidosis. You’ll need your doctor’s help to lower your blood sugar level safely.

Glycated hemoglobin (A1C) test

During an appointment, your doctor may conduct an A1C test. This blood test indicates your average blood sugar level for the past two to three months. It works by measuring the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells.

An A1C level of 7 percent or less means that your treatment plan is working and that your blood sugar was consistently within the target range. If your A1C level is higher than 7 percent, your blood sugar, on average, was above the normal range. In this case, your doctor may recommend a change in your diabetes treatment plan.

However, for some people, especially the elderly, people with other medical conditions, or advanced diabetes complications, a higher A1C level of up to 8 percent may be appropriate.

Keep in mind that the normal range for A1C results may vary somewhat among labs. If you consult a new doctor or use a different lab, it’s important to consider this possible variation when interpreting your A1C test results.

How often you need the A1C test depends on the type of diabetes you have and how well you’re managing your blood sugar. Most people with diabetes, however, receive this test between two and four times a year.

Hyperglycemia treatment

You can often lower your blood glucose level by exercising. However, if your blood glucose is above 240 mg/dl (13 mmol/L), check your urine for ketones. If you have ketones, do not exercise.

Exercising when ketones are present may make your blood glucose level go even higher. You’ll need to work with your doctor to find the safest way for you to lower your blood glucose level.

Cutting down on the amount of food you eat might also help. Work with your dietitian to make changes in your meal plan. If exercise and changes in your diet don’t work, your doctor may change the amount of your medication or insulin or possibly the timing of when you take it.

Emergency treatment for severe hyperglycemia

If you have signs and symptoms of diabetic ketoacidosis and hyperosmolar hyperglycemic syndrome, you may be treated in the emergency room or admitted to the hospital. Emergency treatment can lower your blood sugar to a normal range. Treatment usually includes:

• Fluid replacement. You’ll receive fluids — either orally or through a vein (intravenously) — until you’re rehydrated. The fluids replace those you’ve lost through excessive urination, as well as help dilute the excess sugar in your blood.
• Electrolyte replacement. Electrolytes are minerals in your blood that are necessary for your tissues to function properly. The absence of insulin can lower the level of several electrolytes in your blood. You’ll receive electrolytes through your veins to help keep your heart, muscles and nerve cells functioning normally.
• Insulin therapy. Insulin reverses the processes that cause ketones to build up in your blood. Along with fluids and electrolytes, you’ll receive insulin therapy — usually through a vein.

As your body chemistry returns to normal, your doctor will consider what may have triggered the severe hyperglycemia. Depending on the circumstances, you may need additional treatment.

If your doctor suspects a bacterial infection, he or she may prescribe antibiotics. If a heart attack seems possible, your doctor may recommend further evaluation of your heart.

Home treatment

Talk to your doctor about managing your blood sugar and understand how different treatments can help keep your glucose levels within your goal range. Your doctor may suggest the following treatments:

• Get physical. Regular exercise is often an effective way to control your blood sugar. However, don’t exercise if ketones are present in your urine. This can drive your blood sugar even higher.
• Take your medication as directed. If you have frequent episodes of hyperglycemia, your doctor may adjust the dosage or timing of your medication.
• Follow your diabetes eating plan. It helps to eat less and avoid sugary beverages. If you’re having trouble sticking to your meal plan, ask your doctor or dietitian for help.
• Check your blood sugar. Monitor your blood glucose as directed by your doctor. Check more frequently if you’re ill or you’re concerned about severe hyperglycemia or hypoglycemia.
• Adjust your insulin doses to control hyperglycemia. Adjustments to your insulin program or a supplement of short-acting insulin can help control hyperglycemia. A supplement is an extra dose of insulin used to help temporarily correct a high blood sugar level. Ask your doctor how often you need an insulin supplement if you have high blood sugar.