Diabetes: High Blood Sugar

Hyperglycemia means your blood sugar is too high. It can happen if you miss your diabetes medicine, do not eat healthy foods, or do not exercise. Illness, stress, and hormones can also cause your blood sugar to rise. In some people, it occurs for no apparent reason. If you have type 2 diabetes, it may take days for your blood sugar to rise too high. With type 1 diabetes, it may happen faster. By checking your blood sugar, you may be able to prevent this and avoid an emergency.

Signs of high blood sugar

You may have mild high blood sugar if you:

• Feel very thirsty and urinate more.
• Have warm, dry skin.

You may have moderate high blood sugar if you:

• Breathe fast and deeply.
• Have a fruity breath odor.
• Have belly pain, poor appetite, or vomiting.
• Are dizzy or weak.
• Urinate less.
• Have blurred vision that slowly gets worse.
• Feel drowsy and have trouble waking up.

You may have severe high blood sugar if you:

• Have a rapid heart rate and a weak pulse.
• Have rapid, deep breathing with a strong, fruity breath odor.
• Feel very sleepy and weak.
• Fainted or passed out.

How to prevent high blood sugar

• Post a list of symptoms where you can see it often. Make sure others know the symptoms and what to do in case of an emergency.
• Check your blood sugar often, especially if you are sick or are not doing your normal routine.
• Teach others at work and at home how to check your blood sugar.
• Have a medical alert bracelet or other medical identification with you at all times.
• Develop a plan. Talk with your doctor about how much insulin to take, depending on your blood sugar level.
• Take your medicines as prescribed. Do not skip your diabetes medicine or insulin doses without talking to your doctor first.
• Make sure you stay well hydrated, especially if your blood sugar is high.

Take action if blood sugar is high

If your blood sugar is moderate to severely high (for example, 350 or above):

• Check your blood sugar again to be sure your meter is reading correctly.

• Take your temperature. If it is 100°F (37.8ºC) or above, call your doctor or follow the plan you and your doctor discussed.
• If your meter still reads high:

  • If you have no symptoms, call your doctor right away or do as you and your doctor decided.
  • If you have serious symptoms, call 911 right away.
  • If your blood sugar is returning to normal, follow your usual diabetes plan.

If your blood sugar is mildly high (for example, from 200 to 350) and you are using insulin or other diabetes medicines:

• If you missed your dose of long-acting insulin or another diabetes medicine, take the missed dose.
• If you use insulin, take the medicine that your doctor prescribed. If you and your doctor did not decide this, call your doctor for advice.
• Drink water or calorie-free liquids. Avoid coffee, alcohol, soda pop, and anything with a lot of sugar in it.
• If you are taking insulin, do a test for ketones. This is especially important if your blood sugar is high. Call your doctor if you have moderate or large amounts of ketones in the urine or a high level of blood ketones (for example, more than 0.6 mmol/L).
• If your temperature is 100°F (37.8ºC) or above, call your doctor or follow the plan your doctor gave you.
• Wait 30 minutes after taking insulin or 1 hour after taking another diabetes medicine. Check your blood sugar again:

  • If your blood sugar level goes down, follow your usual diabetes plan.
  • If your blood sugar level stays the same or gets worse and you have serious symptoms, call 911 right away.
  • If your blood sugar level stays the same or gets worse and you do not have symptoms, call your doctor right away.

If your blood sugar is mildly high (for example, from 200 to 350) and you are not using medicine:

• Do not eat any foods with sugar or carbohydrates.
• Drink water or calorie-free liquids. Avoid coffee, alcohol, soda pop, and anything with a lot of sugar in it.
• If your temperature is 100°F (37.8ºC) or above, call your doctor or follow the plan your doctor gave you.
• Check your blood sugar again right away if you have serious symptoms. Call your doctor if your blood sugar didn't go down or stayed the same.
• Check your blood sugar again in 30 minutes if you do not have symptoms. Call your doctor if your blood sugar didn't go down or stayed the same.
• If blood sugar is returning to normal, follow your usual diabetes plan.

If your blood sugar is often above your target range:

• Ask yourself if you are taking your medicines and following your eating plans. If you are, talk to your doctor. You may need to adjust your medicine.
• If your doctor hasn't given you specific targets for blood sugar levels, use these as a general guideline:

  • 80 to 130 before meals.
  • Less than 180, 1 to 2 hours after meals.