High Blood Sugar in Diabetes

Your body turns the food you eat into glucose (sugar), which it uses for energy. But if your body isn’t able to use the sugar right away, it can build up in your blood and lead to high blood sugar.

Education Topics

Prevention

How can you prevent high blood sugar?

  • Watch your weight. If you’re overweight, losing just a small amount of weight may help. Reducing fat around your waist is most important.
  • Limit the amount of calories, sweets, and unhealthy fat you eat. Ask your doctor if a dietitian can help you. A registered dietitian can help you create meal plans that fit your lifestyle.
  • Get at least 30 minutes of exercise on most days of the week. Exercise helps control your blood sugar. It also helps you maintain a healthy weight. Walking is a good choice. You also may want to do other activities, such as running, swimming, cycling, or playing tennis or team sports.
  • If your doctor prescribed medicines, take them exactly as prescribed. Call your doctor if you think you are having a problem with your medicine. You will get more details on the specific medicines your doctor prescribes.

Self-care Treatment

What should you do after an episode of high blood sugar?

Take the following steps after your blood sugar level has returned to a target range. Continue medicine as prescribed by your doctor. Check blood sugar levels as directed. Report the episode to your doctor. And drink extra liquids. Water and sugar-free drinks are best.

Self-care Treatment Options

How can you treat high blood sugar?

You can get high blood sugar for many reasons, including not taking your diabetes medicines, eating more than usual (especially sweets), not exercising, or being sick or under a lot of stress.

Common symptoms of high blood sugar include:

  • Being very thirsty.
  • Urinating a lot.
  • Losing weight without trying.
  • Having blurry vision.

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

To 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.

Treating high blood sugar

Your doctor will give you goals for your blood sugar and recommend ways to treat high blood sugar. Here are some general guidelines for treating it.

  • Treat mild to moderate high blood sugar.

    Follow these steps if your blood sugar is over the target range set by your doctor. For example, that might be over 200 mg/dL for two or more readings a few hours apart.

    • If you missed your usual dose of diabetes medicine, take the missed dose.
    • If your doctor prescribed a dose of fast-acting insulin based on the blood sugar level (sliding scale), give the appropriate dose. If not, call your doctor for advice.
    • Test for ketones, if your doctor has advised you to do so. Call your doctor if the results show a moderate-to-large amount of ketones.
    • Wait 30 minutes after giving the extra insulin or the missed medicine. Then check your blood sugar again.
    • Drink extra liquids to replace the fluids lost through the urine. Water and sugar-free drinks are best.
  • Know when to take action.
    • If symptoms of high blood sugar become more noticeable or if your blood sugar level continues to rise, call your doctor.
    • If you start to feel drowsy or disoriented or if your blood sugar continues to rise (for example, above 350 mg/dL), call 911 or other emergency services immediately. It's best to have someone with you if your blood sugar is this high so that the person can call for you.
  • Recheck extremely high blood sugar.

    Follow these steps if your blood sugar is extremely high—for example, over 600 mg/dL. Some blood sugar meters read only levels up to about 400 mg/dL.

    • Wash and dry the finger carefully before checking again.
    • If the meter reads high, test the accuracy of the meter, and then recheck the blood sugar.
    • If the meter reads high again, call the doctor for advice or seek emergency care.

Signs and Symptoms

What are the symptoms of high blood sugar?

High blood sugar (hyperglycemia) most often occurs in people who have diabetes that isn't well controlled. The symptoms of high blood sugar can be mild, moderate, or severe.

Young children are not able to recognize symptoms of high blood sugar. Parents need to do a home blood sugar test on their child whenever they suspect high blood sugar.

Mild high blood sugar

You may have mild symptoms if your blood sugar levels are consistently higher than your target range. Some people may not notice any symptoms when their blood sugar level is in this range.

The main symptoms of mild high blood sugar are:

  • Increased thirst.
  • Increased urination.
  • Weight loss.
  • Fatigue.

Moderate to severe high blood sugar

You may have moderate to severe symptoms if your blood sugar levels are consistently high. These symptoms include:

  • Blurred vision.
  • Extreme thirst.
  • Lightheadedness.
  • Flushed, hot, dry skin.
  • Restlessness, drowsiness, or difficulty waking up.

People with type 1 diabetes and some people with type 2 diabetes produce little or no insulin. These people may also have:

  • Rapid, deep breathing.
  • A fast heart rate and a weak pulse.
  • A strong, fruity breath odor.
  • Loss of appetite, belly pain, and/or vomiting.

If your blood sugar levels continue to rise, you may:

  • Become confused and sluggish.
  • Pass out (lose consciousness) if your blood sugar levels are very high.

Treatment Options

How is high blood sugar treated?

You can take steps to lower your blood sugar level if you understand what makes it get higher. Your doctor may want you to learn how to test your blood sugar level at home. Then you can see how illness, stress, or different kinds of food or medicine raise or lower your blood sugar level.

Other tests may be needed to see if you have diabetes.

What Causes It

What non-diabetes medicines raise blood sugar?

Some medicines for conditions other than diabetes can raise your blood sugar level. This is a concern when you have diabetes. Make sure every doctor you see knows about all of the medicines, vitamins, or herbal supplements you take. This means anything you take with or without a prescription.

Examples include:

  • Thiazide diuretics.
  • Corticosteroids.
  • Birth control pills (oral contraceptives) and progesterone.
  • Catecholamines.
  • Decongestants, such as pseudoephedrine.
  • The B vitamin niacin. The risk of high blood sugar from niacin lowers after you have taken it for a few months.
  • Some antipsychotic medicines.

What causes high blood sugar?

Sugar (glucose) can build up in your blood if you:

  • Have insulin resistance.
  • Don't take enough insulin or miss a dose of your diabetes medicine.
  • Take certain medicines, such as steroids.

What can cause high blood sugar when you have diabetes?

Many things can cause high blood sugar. For example, it may happen if you skip a dose of diabetes medicine or insulin, eat too much, exercise less than usual, are stressed or ill, or are pregnant. Plus, some medicines raise blood sugar as a side effect.

What It Is

What is high blood sugar?

Your body turns the food you eat into glucose (sugar), which it uses for energy. But if your body isn’t able to use the sugar right away, it can build up in your blood and lead to high blood sugar.

When the amount of sugar in your blood stays too high for too much of the time, you may have diabetes. Diabetes is a disease that can cause serious health problems.

The good news is that lifestyle changes may help you get your blood sugar back to normal and avoid or delay diabetes.

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