Hyperglycemia (High Blood Sugar)

Important Information

  • Review your blood sugar logs to look for patterns of BG over 140-150 mg/dL.
  • A very high BG is anything over 300 mg/dL.
  • One very high blood sugar number, as long as you feel okay, is not an immediate cause of concern.
  • 2 or more very high blood sugar numbers means you need to start figuring out why your number is so high.
  • Test for ketones when you have more than two very high blood sugar numbers in a row.

General Information

In general, any level over 140-150 mg/dL is a high level.  You do not necessarily need to do anything about this level beyond watching to make sure that a pattern of levels at or above this range doesn’t develop.  If you notice that your BG levels are rising, you can call the diabetes clinic for some help in making changes to fix these levels.

At some point everyone with diabetes will have a very high blood sugar level.  We define very high as any level over 300 mg/dL.

Symptoms

  • Extreme thirst 
  • Need to urinate often 
  • Blurry vision 
  • Dry skin 
  • Hunger
  • Drowsy 
  • Slowly healing wounds

What to do with a Very High Blood Sugar

One very high blood sugar level is not a cause for panic.  Rather, it should serve as an alarm signaling the need for additional blood glucose monitoring and depending upon how you treat your diabetes; it may also mean that you need to take some extra insulin.

Very high blood sugar levels mean that the body does not have enough insulin around to use sugar as energy.  Even though the level of sugar in the blood stream is very high, the body cells may be sending out the alarm that they are starving.  In this case, the body will switch to burning fat as an energy source.  This is a problem because excess burning creates byproducts such as ketones and acids. After several hours the blood can become too acidic for the body organs to work right.  This leads to a life-threatening diabetes emergency called Diabetic Ketoacidosis (DKA). Full-blown DKA must be treated in a hospital, often in the Intensive Care Unit.

It is important to know that you must start monitoring for ketones right away (as soon as you have 2 or more blood sugar levels over 300 mg/dL) and follow the steps in the table below or call the diabetes team for assistance, you can often prevent the development of Diabetic Ketoacidosis.

Blood glucose

< 140 mg/dL

140-300mg/dL

>300mg/dL

Should I check ketones?

No. Unless you are very sick with a bad cold, flu or stomach bug

No. Unless you are very sick with a bad cold, flu or stomach bug

Yes – if this is your second high blood sugar in a row

What do I do if I have a trace of small ketones?

Drink Water

Drink Water

Drink water.

What do I do if I have moderate to large ketones?

Call the Diabetes Team. You might need more insulin to help clear the ketones.

Call the Diabetes Team.  You might need more insulin to help clear the ketones

Call the Diabetes Team.  You might need more insulin to help clear the ketones

When do I check a repeat blood sugar?

 2 hours

2 hours

2 hours