Type 1 Diabetes and Hyperglycemia: Handling High Blood Sugar

One of the hallmarks of type 1 diabetes[1] is hyperglycemia[2], or high blood glucose (sugar). There’s a very good reason that glucose levels climb high in type 1 diabetes, and that’s a lack of insulin[3]. When the pancreas shuts down insulin production, blood glucose levels start to climb. If there is sufficient insulin in the bloodstream, say, from an insulin injection or insulin infusion from a pump, glucose levels (hopefully) return to a safe level. If there is little or no insulin available, the situation becomes serious, both in the short term and the long term.

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Symptoms of hyperglycemia

How do you know if your blood sugar is too high? Chances are you’ve experienced hyperglycemia and you’ve had some telling symptoms. The most common signs and symptoms of hyperglycemia[5] are:

· Feeling thirsty

· Feeling hungry (even “hangry”)

· Frequent urination

· Blurry vision

· Feeling very tired and lethargic

· Headache[6]

If your blood sugars are high for a longer period of time, you might realize that you’ve lost weight — despite eating your usual meals and snacks, or even eating more than usual because you’ve been hungry. You might also find yourself with a yeast infection or a urinary tract infection[7], or a cut or a sore that seems to be taking forever to heal.

Blood glucose levels can get very high (more on that in a moment) and at this point, you may develop some more serious symptoms, such as:

· Nausea or vomiting

· Stomach pain

· Shortness of breath

· Fruity-smelling breath

· Confusion

· Weakness

What causes hyperglycemia?

If you have type 1 diabetes, it’s almost inevitable that you will have hyperglycemia at some point. Obviously, the goal is to minimize episodes of hyper- and hypoglycemia[8] as much as possible, keeping glucose levels in a safe range for as long as possible. But doing so requires education, support — and a lot of detective work on your part.

Some common factors causing hyperglycemia include:

· Not enough insulin

· Not injecting insulin properly

· Using expired insulin

· In pump users, a displaced infusion set or a kink in the infusion set or tubing

· Changes in food intake; for example, eating too much carbohydrate, eating higher-fat foods, eating more often or eating larger amounts of food

· A decrease in your usual level of physical activity[9]

But other things can lead to high blood glucose levels, as well, and these may not be what initially comes to mind. Examples include:

· Being under stress[10] due to, say, issues at work, school or home; losing a job; or getting divorced

· Illness[11], such as a cold or sinus infection, or something more serious, like having the flu or appendicitis, for example

· Injury, such as a sprained ankle

· Changes in your sleep[12]. Burning the midnight oil, insomnia or a noisy sleeping partner can disrupt your sleep which, in turn, can cause hormonal changes that spike glucose levels.

· Menstrual cycle[13]. Some women find that hyperglycemia occurs a few days before their period.

· Medication. Certain non-diabetes medications can raise blood sugar, especially steroids (e.g., prednisone[14]), thiazide diuretics, some antipsychotic medications, some antibiotics, and decongestants.

Hyperglycemia can also occur as a rebound from a low blood sugar[15]. If your blood sugar drops, counterregulatory hormones may kick in, signaling the liver to release glucose. You might also have hyperglycemia if you over-treat a low.

Psychosocial issues may lead to hyperglycemia, too. Diabulimia[16], an eating disorder in a person with diabetes (typically type 1 diabetes) is a form of bulimia whereby the person intentionally restricts or omits insulin in order to lose weight. Some people may omit insulin injections in public situations, such as in a restaurant or at work due to inconvenience, embarrassment or a desire to not let others know about their diabetes. Alcohol[17] abuse is another instance that can lead to hyperglycemia.

Finally, economic challenges are a factor that can lead to hyperglycemia. The inability to afford insulin[18] can affect being able to take the prescribed amount of insulin.

How high is “high”?

Hopefully your diabetes care team[19] has discussed your blood sugar[20] goals with you (and if not, make a point to ask at your next appointment). Your own blood sugar goals may be different based on your age and other health conditions. However, here are general hyperglycemia definitions:

Fasting hyperglycemia

The American Diabetes Association defines a fasting glucose target as 80 to 130 mg/dl. A fasting glucose level above 130 mg/dl is considered to be hyperglycemia.

Postprandial hyperglycemia

A blood glucose level that’s above 180 mg/dl one to two hours after eating a meal (postprandial) is considered to be hyperglycemia.

Symptoms of hyperglycemia usually appear when glucose levels are at least 180 to 200. Keep in mind that you may not have all of the symptoms of hyperglycemia. Checking your blood glucose with a meter is crucial for you to understand how well your diabetes is managed and if your blood glucose is within your target range. Likewise, many people with type 1 diabetes now use CGM (continuous glucose monitoring)[21], which, depending on the type of CGM used, can reduce or practically eliminate the need to do fingersticks.


When blood glucose level go above 250 mg/dl, your healthcare team may advise you to check your urine for ketones[22]. Ketones form when fat, rather than glucose, is used for energy. This can happen when there isn’t enough insulin available. Ketone levels can build up in the blood, making it more acidic; if levels get too high, you’re at risk for developing DKA (diabetic ketoacidosis[23]). DKA is a very serious condition that typically needs to be treated in the hospital. Ask your doctor or diabetes educator[24] about when and how to check for ketones, and what to do if you have moderate to high levels of ketones in your urine.

Treating hyperglycemia

Untreated hyperglycemia has both short- and long-term consequences. The short-term, or “acute,” consequences of hyperglycemia are the typical signs and symptoms, such as thirst, urination and headache that tend to make you feel unwell. However, another acute consequence that is much more dangerous is DKA.

Chronic hyperglycemia can lead to a series of diabetes complications[25], including:

· Heart disease[26]

· Nerve damage (neuropathy)[27]

· Kidney disease[28] and failure (nephropathy)

· Eye disease and potential blindness (diabetic retinopathy[29])

· Foot problems[30], including a higher risk of amputation

· Teeth and gum problems[31]

Treating hyperglycemia really depends on the situation. A few high blood sugar levels here and there may be related to food choices[32], not doing your usual level of physical activity, or forgetting an insulin injection, for example. The treatment? Getting back on track with your eating plan and/or your usual exercise routine, as well as taking your insulin as prescribed.

More specific treatment guidelines are needed if you’re sick or recovering from a medical procedure. In this case, it’s important to have a “sick-day plan” in place. A sick-day plan is developed in conjunction with your doctor or diabetes educator, and includes how often to check your blood sugar, foods to eat, how to adjust your insulin, and when to call the doctor or even go to the hospital based on blood sugar readings and specific symptoms.

Other steps you can take include:

· Double-checking your insulin to make sure it hasn’t expired or “spoiled” from being left in a hot car, for example. You may need to use a new vial of insulin or insulin pen; if you use a pump, it’s a good idea to use a new infusion set, as well.

· Drinking plenty of non-caloric fluids, as you may be somewhat dehydrated.

· Cutting back a little on your carb intake (but don’t cut out carbs completely).

· Going for a walk[33] or doing some activity to help lower your blood sugar levels. However, it’s best not to exercise if you have ketones in your urine; if you do, exercise may cause your glucose levels to go even higher.

You might also need to address any other factors that you suspect might be causing your high glucose levels, such as other medications, level of stress, poor sleep and challenges affording your insulin. Talking with your doctor and other members of your diabetes care team can be helpful in dealing with these issues.

Want to learn more about dealing with high blood sugar? Read “Strike the Spike II: How to Manage High Blood Glucose After Meals”[34] and “Managing Hyperglycemia.”[35]

  1. type 1 diabetes: https://www.diabetesselfmanagement.com/diabetes-resources/definitions/type-1-diabetes/
  2. hyperglycemia: https://www.diabetesselfmanagement.com/managing-diabetes/blood-glucose-management/managing-hyperglycemia/
  3. insulin: https://www.diabetesselfmanagement.com/blog/what-does-insulin-do/
  4. sign up for our free newsletter: https://www.diabetesselfmanagement.com/newsletter/
  5. signs and symptoms of hyperglycemia: https://www.diabetesselfmanagement.com/about-diabetes/types-of-diabetes/six-type-1-diabetes-symptoms-you-need-to-know/
  6. Headache: https://www.diabetesselfmanagement.com/blog/five-ways-diabetes-causes-headaches/
  7. urinary tract infection: https://www.diabetesselfmanagement.com/managing-diabetes/womens-health/diabetes-and-chronic-utis-diabetes-questions-answers/
  8. hypoglycemia: https://www.diabetesselfmanagement.com/managing-diabetes/blood-glucose-management/what-is-hypoglycemia-symptoms-treatments/
  9. physical activity: https://www.diabetesselfmanagement.com/nutrition-exercise/exercise/
  10. stress: https://www.diabetesselfmanagement.com/blog/three-ways-to-cope-with-stress-2/
  11. Illness: https://www.diabetesselfmanagement.com/about-diabetes/diabetes-basics/planning-ahead-for-sick-days/
  12. sleep: https://www.diabetesselfmanagement.com/managing-diabetes/general-health-issues/getting-the-sleep-you-need/
  13. Menstrual cycle: https://www.diabetesselfmanagement.com/blog/diabetes-period-2/
  14. prednisone: https://www.diabetesselfmanagement.com/about-diabetes/general-diabetes-information/the-link-between-prednisone-and-diabetes/
  15. rebound from a low blood sugar: https://www.diabetesselfmanagement.com/blog/dawn-phenomenon-somogyi-effect-can/
  16. Diabulimia: https://www.diabetesselfmanagement.com/about-diabetes/general-diabetes-information/diabulimia/
  17. Alcohol: https://www.diabetesselfmanagement.com/blog/drinking-and-diabetes-seven-facts-to-know/
  18. afford insulin: https://www.diabetesselfmanagement.com/blog/insulin-prices-four-ways-pay-less/
  19. diabetes care team: https://www.diabetesselfmanagement.com/about-diabetes/diabetes-basics/diabetes-support-system/members-diabetes-care-team/
  20. blood sugar: https://www.diabetesselfmanagement.com/managing-diabetes/blood-glucose-management/blood-sugar-chart/
  21. CGM (continuous glucose monitoring): https://www.diabetesselfmanagement.com/managing-diabetes/blood-glucose-management/cgm-diabetes-management/
  22. ketones: https://www.diabetesselfmanagement.com/managing-diabetes/blood-glucose-management/getting-to-know-ketones/
  23. diabetic ketoacidosis: https://www.diabetesselfmanagement.com/managing-diabetes/blood-glucose-management/diabetic-ketoacidosis/
  24. diabetes educator: https://www.diabetesselfmanagement.com/about-diabetes/diabetes-basics/certified-diabetes-educator/
  25. diabetes complications: https://www.diabetesselfmanagement.com/managing-diabetes/complications-prevention/
  26. Heart disease: https://www.diabetesselfmanagement.com/managing-diabetes/complications-prevention/lower-risk-heart-disease/
  27. Nerve damage (neuropathy): https://www.diabetesselfmanagement.com/managing-diabetes/complications-prevention/diabetic-neuropathy/
  28. Kidney disease: https://www.diabetesselfmanagement.com/blog/ten-things-know-kidney-disease/
  29. diabetic retinopathy: https://www.diabetesselfmanagement.com/managing-diabetes/complications-prevention/eating-for-better-vision-and-healthy-eyes/diabetic-retinopathy/
  30. Foot problems: https://www.diabetesselfmanagement.com/managing-diabetes/complications-prevention/caring-for-your-feet-when-you-have-diabetes/
  31. Teeth and gum problems: https://www.diabetesselfmanagement.com/managing-diabetes/complications-prevention/diabetes-oral-health/
  32. food choices: https://www.diabetesselfmanagement.com/nutrition-exercise/meal-planning/
  33. a walk: https://www.diabetesselfmanagement.com/nutrition-exercise/exercise/health-benefits-of-walking/
  34. “Strike the Spike II: How to Manage High Blood Glucose After Meals”: https://www.diabetesselfmanagement.com/managing-diabetes/blood-glucose-management/manage-high-blood-glucose/
  35. “Managing Hyperglycemia.”: https://www.diabetesselfmanagement.com/managing-diabetes/blood-glucose-management/managing-hyperglycemia/

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