High blood sugar, which affects people who have diabetes.


Check blood sugar as often as a health care professional recommends. Get regular exercise. Take any diabetes medicines as prescribed. Eat a balanced diet with smaller portions and less sugar.

When to seek immediate medical care

Seek emergency help if a person with hyperglycemia has:

  • Ongoing vomiting or diarrhea, and can't keep down food or liquids.
  • Blood sugar levels that stay above 240 milligrams per deciliter (mg/dL).
  • Acids called ketones in the urine, found with an at-home urine ketones test kit.

When to make a doctor's appointment

Make an appointment to see a health care professional if the person has:

  • Ongoing diarrhea or vomiting, but can keep down some food or drinks.
  • A fever that lasts longer than 24 hours.
  • Blood sugar levels that stay above 240 mg/dL despite treatment, along with ketoacidosis symptoms such as extreme thirst and urinating often.
  • Trouble keeping blood sugar within the prescribed target range.