Symptoms of high blood sugar

Mild high blood sugar

If your blood sugar levels are consistently 200 milligrams per deciliter (mg/dL) to 350 mg/dL, you may have mild symptoms of high blood sugar. You may urinate more than usual if you are drinking plenty of liquids. Some people with diabetes may not notice any symptoms when their blood sugar level is in this range.

Young children are unable 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.

If you do not drink enough liquids to replace the fluids lost from high blood sugar levels, you can become dehydrated. Young children can become dehydrated very quickly. Symptoms of dehydration include:

  • A dry mouth and increased thirst.
  • Warm, dry skin.

Moderate to severe high blood sugar

If your blood sugar levels are consistently high (usually above 350 mg/dL), you may have moderate to severe symptoms of high blood sugar. You may have blurred vision and fatigue. If you are not drinking enough liquids, you may also have symptoms of dehydration, such as the following:

  • Dizziness or weakness when sitting or standing
  • Dark, concentrated urine in decreasing amounts
  • Lightheadedness

If your body produces little or no insulin (people with type 1 diabetes and some people with type 2 diabetes), you also may have the following symptoms:

  • Rapid, deep breathing
  • A fast heart rate and a weak pulse
  • A strong, fruity breath odor (similar to the smell of nail polish remover or acetone)
  • Loss of appetite, abdominal pain, and/or vomiting

If your blood sugar levels continue to rise, you may become confused and lethargic. You also may become unconscious if your blood sugar levels are very high.

Last Updated: September 24, 2008

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