If you have signs or symptoms of low blood sugar, check your blood sugar level with a blood glucose meter — a small device that measures and displays your blood sugar level. You have hypoglycemia when your blood sugar level drops below 70 milligrams per deciliter (mg/dL) (3.9 millimoles per liter (mmol/L)).
If you think your blood sugar may be dipping too low, check your blood sugar level with a blood glucose meter. If you have symptoms of low blood sugar but can't check your blood sugar level right away, assume your blood sugar is low and treat for hypoglycemia.
- Eat or drink carbohydrates
Eat or drink something that's mostly sugar or carbohydrates to raise your blood sugar level quickly. Pure glucose — available in tablets, gels and other forms — is the preferred treatment.
Foods with more fat, such as chocolate, don't raise blood sugar as quickly. And diet soft drinks cannot be used to treat an episode of hypoglycemia because they don't have any sugar.
Examples of foods that do raise your blood sugar level quickly include:
- Four glucose tablets (available without a prescription at most pharmacies)
- A serving of glucose gel (read the label for amount)
- Five to 6 pieces of hard candy or jelly beans (check the food label for the exact serving)
- Four ounces (120 milliliters) of fruit juice or regular — not diet — soda
- One tablespoon (15 milliliters) of sugar, corn syrup or honey
In general, food or drink with 15 to 20 grams of carbohydrates is often enough to raise your blood sugar levels back into a safe range.
- Recheck your blood sugar level
Check your blood sugar level 15 minutes after eating or drinking something to treat your hypoglycemia. If your blood sugar is still low, eat or drink another 15 to 20 grams of carbohydrates. Repeat this pattern until your blood sugar is above 70 mg/dL (3.9 mmol/L).
- Have a snack or meal
Have a snack or a meal to keep your blood sugar from dropping again. If you typically take insulin with food, you generally don't need additional insulin if you're eating a snack after having a low blood sugar level. If you're going to eat a meal, however, you may need a reduced dose of insulin to ensure that your blood sugar doesn't rise too quickly.
It's important to try not to overtreat your low blood sugar. If you do, you may cause your blood sugar level to rise too high, which will make you feel thirsty and tired.
Glucagon is a hormone that raises blood sugar quickly. It can be lifesaving if someone isn't alert enough to eat or drink something to raise his or her blood sugar. Glucagon is available only by prescription.
Glucagon comes in an emergency syringe kit or as a pre-mixed injection that is ready to use. Glucagon is also available as a powdered nasal spray given in one nostril. Store glucagon as directed on the packaging and be aware of the expiration date. When given to someone who is unconscious, the person should be turned on his or her side to prevent choking in case of vomiting.
About 15 minutes after getting glucagon, the person should be alert and able to eat. If someone doesn't respond within 15 minutes, call emergency medical care. If someone quickly responds to glucagon, it's still recommended that you contact his or her diabetes health care provider promptly.
If you've had a low blood sugar episode that was serious enough to require help from others, your health care provider will likely want to figure out if your insulin or other diabetes medication needs to be adjusted to prevent another serious episode.
Some people have frequent and severe hypoglycemia despite medication adjustments. In these circumstances, your health care provider may recommend that you keep your blood sugar in a higher than usual range.
Your provider may also suggest that you use a continuous glucose monitor — a device that measures your blood sugar every few minutes using a sensor inserted underneath the skin. Your health care provider will also likely recommend that you have glucagon with you at all times. Teach people you trust, such as family, friends and close co-workers, how to use it.
Continuous glucose monitor and insulin pump
Some people don't have or don't recognize early symptoms of hypoglycemia (hypoglycemia unawareness). If you have hypoglycemia unawareness, your health care provider may recommend a higher glucose target range.
It's also very important to check your blood sugar consistently before going to bed and to have a snack containing carbohydrates before going to sleep if your blood sugar is lower than your bedtime target. Your health care provider may also recommend a continuous glucose monitor that can sound an alarm when your blood sugar is dropping.
Teach people how to help
Inform people you trust, such as family, friends and co-workers, about hypoglycemia. If others know what symptoms to look for, they might be able to alert you to early symptoms. It's important that family members and close friends know where you keep glucagon and how to give it so that a potentially serious situation can be easier to safely manage.
Always carry a low blood sugar treatment with you, such as glucose tablets, hard candy or gel. Also carry glucagon if it's prescribed for you.
Wear a medical ID
It's a good idea to wear a necklace or bracelet and have a wallet card that identifies you as someone who has diabetes.
Preparing for your appointment
If you have low blood sugar levels several times a week, make an appointment with your health care provider. Together you can determine what's leading to your hypoglycemia and figure out what changes to make to prevent it.
Here's some information to help you get ready for your appointment.
What you can do
- Be aware of pre-appointment restrictions. Sometimes you need to not eat or drink anything but water for 8 to 12 hours (fast) for blood tests. When you make the appointment, ask if fasting is necessary. If it is, ask what changes you need to make to your diabetes management because you're not eating or drinking.
- Make a list of your symptoms and how often they occur. It helps to keep a record of your blood sugar readings and low blood sugar reactions so that you and your health care provider can see patterns leading to hypoglycemia.
- Make a list of key personal information, including major stresses or recent life changes. If you're monitoring your glucose values at home, bring a record of the glucose results, detailing the dates and times of testing.
- Make a list of medications, vitamins and supplements you take.
- Create a record of blood glucose meter values. Give your health care provider a written or printed record of your blood sugar levels, times and medication.
- Take your glucose meter with you. Some meters allow your provider's office to download the recorded glucose values.
- Write down questions to ask your health care provider. Ask your provider about any parts of your diabetes management plan where you need more information.
Questions you may want to ask include:
- How often do I need to check my blood sugar?
- What is my target blood sugar range?
- How do diet, exercise and weight changes affect my blood sugar?
- How can I prevent low blood sugar?
- Do I need to worry about high blood sugar? What are the signs and symptoms I need to watch out for?
- Do I need a prescription for emergency glucagon?
- If I continue having hypoglycemia, when do I need to see you again?
Don't hesitate to ask other questions.
What to expect from your doctor
Your health care provider is likely to ask you a number of questions, such as:
- What symptoms do you notice when you have low blood sugar?
- How often do you have these symptoms?
- What do you do to raise your blood sugar levels?
- What's a typical day's diet like?
- Are you exercising? If so, how often?
- Do your family, friends and co-workers know what to do if you have severe hypoglycemia?
May 06, 2022
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- Melmed S, et al. Hypoglycemia. In: Williams Textbook of Endocrinology. 14th ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed Feb. 17, 2020.
- Hypoglycemia (low blood sugar). American Diabetes Association. https://www.diabetes.org/healthy-living/medication-treatments/blood-glucose-testing-and-control/hypoglycemia. Accessed Jan. 19, 2022.
- Mahoney GK, et al. Severe hypoglycemia attributable to intensive glucose-lowering therapy among US adults with diabetes: Population-based modeling study, 2011-2014. Mayo Clinic Proceedings. 2019; doi:10.1016/j.mayocp.2019.02.028.
- Cryer PE, et al. Hypoglycemia in adults with diabetes mellitus. https://www.uptodate.com/contents/search. Accessed Feb. 16, 2020.
- Castro MR (expert opinion). Mayo Clinic. Feb. 19, 2022.