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Healtheuniversity > English > Diabetes College > Treat Diabetes > Manage Your Blood Sugar > What is High Blood Sugar (Hyperglycemia)?

What is High Blood Sugar (Hyperglycemia)?

High blood sugar means your blood sugar is higher than normal. Over time, high blood sugar leads to serious health problems.

  • Check your blood sugar if you think it is high.
  • Check your blood sugar more often when you are ill (cold, infection, surgery).
  • Get medical help right away if you get very high blood sugar. Very high blood sugar can be a sign of a serious and deadly health problem called diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS).

High blood sugar means your blood sugar level is higher than normal.

Over time, too much sugar in your blood leads to serious health problems (diabetes complications). High blood sugar is also known as hyperglycemia. 

What Are The Signs Of High Blood Sugar?

Everyone has different signs of high blood sugar. You may have any number of the signs listed below.

High blood sugar signs may include:

  • being thirsty
  • feeling tired
  • needing to pee more
  • having an upset stomach, or stomach pain
  • vomiting
  • having blurry vision

Many people do not have signs of high blood sugar. 

Check your blood sugar more often if you are ill, have an infection or are undergoing surgery. Talk to your doctor and make a plan for how to manage your diabetes when you are ill.

What Is The Impact Of High Blood Sugar?

Over time, too much sugar in your body can lead to serious health problems (diabetes complications) like heart attack, stroke, kidney failure, blindness or amputation. 

  • Very high blood sugar can be a sign of a serious and deadly health problem called diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS). This health problem is not common. Get medical help right away if you get this health problem.

Get medical help if you have signs of high blood sugar and are ill. Talk to your doctor about how to manage your diabetes when you are ill.

It is crucial that you know how well your diabetes medicines and healthy habits are helping you to control your blood sugar and reach your A1c target (a measure of your blood sugar control). Many people do not have the signs of high blood sugar. It is important to check your blood sugar regularly so that you know how well you are managing your diabetes between A1c tests. Talk to your doctor about how often you should check your blood sugar.

Last Reviewed: 10/16/2016