Low Blood Sugar (Hypoglycemia)

Fast-acting sugar can be a glass of nonfat milk.

Having too little sugar (glucose) in your blood is called low blood sugar (hypoglycemia). Low blood sugar often means anything lower than 70 mg/dL. Talk with your healthcare provider about your target range. Ask what level is too low for you. Diabetes itself doesn’t cause low blood sugar. But some treatments for diabetes may raise your risk for it. These include pills or insulin. Low blood sugar may make you pass out or have a seizure. So always treat low blood sugar right away. But don't overeat.

Special note: Always carry a source of fast-acting sugar and a snack in case of hypoglycemia.

What you may notice

If you have low blood sugar, you may have one or more of these symptoms:

  • Shakiness or dizziness

  • Cold, clammy skin or sweating

  • Feeling hungry

  • Headache

  • Nervousness

  • A hard, fast heartbeat

  • Weakness

  • Confusion or irritability

  • Blurred eyesight

  • Having nightmares or waking up confused or sweating

  • Numbness or tingling in the lips or tongue

What you should do

Here are tips to follow if you have hypoglycemia: 

  • First check your blood sugar. If it's too low (out of your target range), eat or drink 15 to 20 grams of fast-acting sugar. This may be 3 to 4 glucose tablets, 4 ounces (half a cup) of fruit juice or regular (nondiet) soda, or 1 tablespoon of honey. Don’t take more than this, or your blood sugar may go too high.

  • Don't eat foods high in protein such as milk or nuts to treat hypoglycemia. Protein may increase your insulin response. It may lower your blood sugar even more.

  • Wait 15 minutes. Then recheck your blood sugar if you can.

  • If your blood sugar is still too low, repeat the steps above and check your blood sugar again. If your blood sugar still has not gone back to your target range, contact your healthcare provider. Or seek emergency care.

  • Once your blood sugar is back at target range, eat a snack or meal.

Preventing low blood sugar

Things you can do include the following: 

  • If your condition needs a strict treatment plan, eat meals and snacks at the same times each day. Don’t skip meals!

  • If your treatment plan lets you change when and what you eat, learn how to change the time and dose of your rapid-acting insulin to match this. 

  • Ask your healthcare provider if it's safe to drink alcohol. Never drink on an empty stomach.

  • Take your medicine at the prescribed times.

  • Always carry a source of fast-acting sugar and a snack when you’re away from home.

  • If you have had several hypoglycemic episodes, talk with your healthcare provider. See if you may be able to take less medicine. You also may have a condition where you no longer recognize the symptoms of low blood sugar until the value falls to dangerous levels.

Other things to do

Other tips include:

  • Carry a medical ID card or wear a medical alert bracelet or necklace. It should say that you have diabetes. It should also say what to do if you pass out or have a seizure.

  • Make sure your family, friends, and coworkers know the signs of low blood sugar. Tell them what to do if your blood sugar falls very low and you can’t treat yourself.

  • Keep a glucagon emergency kit handy. Be sure your family, friends, and coworkers know how and when to use it. Check it often. Replace the glucagon before it expires.

  • Talk with your healthcare team about other things you can do to prevent low blood sugar.

If you have unexplained hypoglycemia or hypoglycemia several times, call your healthcare provider.

Online Medical Reviewer: Marianne Fraser MSN RN
Online Medical Reviewer: Raymond Kent Turley BSN MSN RN
Online Medical Reviewer: Robert Hurd MD
Date Last Reviewed: 11/1/2018
© 2000-2021 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.