How Do You Manage Low Blood Sugar if You Have Diabetes?

If you live with diabetes, you’re probably familiar with hypoglycemia, or low blood glucose. This is when your blood glucose (sugar) is less than 70 mg/dl. Using a glucometer (blood glucose meter) is one of the best ways to know if your glucose is out of range. Wearing a continuous glucose monitor (CGM) is another good way to keep track of your glucose.

Common symptoms of hypoglycemia include sweating, shaking, hunger, fast heartbeat, and anxiety. While hypoglycemia can feel different for each person, mild to moderate symptoms are usually treatable with fast-acting sugars. 

Here, you’ll learn more about hypoglycemia, how it can affect you, and the best ways to treat and prevent it. 

What is hypoglycemia?

Hypoglycemia happens when the levels of glucose in your blood are lower than they should be. Because glucose is a main energy source for the body’s cells, when it’s less than 70 mg/dl, you may notice some physical and mental changes. 

Hypoglycemia is most commonly caused by diabetes, including Type 1 diabetes (T1D), Type 2 diabetes (T2D), and gestational diabetes. Diabetes is a constant balancing act of medications, food, exercise, and other factors. Because of this, blood glucose is always changing and can be hard to keep within target range.

Low blood sugar symptoms

If you have hypoglycemia, you may notice symptoms that can feel uncomfortable. They can be physical, such as sweating and shaking. They can also affect your thinking or mood, like confusion and nervousness. Anyone with diabetes can get hypoglycemia, and symptoms can vary from episode to episode. 

The most common symptoms of hypoglycemia include: 

• Hunger

• Fast heartbeat

• Shakiness

• Anxiety

• Sweating

• Tingling

• Dizziness

• Weakness

• Drowsiness

• Confusion

If you suspect hypoglycemia, follow these three steps:

1. Check your glucose. Test with a glucometer or look at your CGM to make sure your glucose is within range.

2. Treat hypoglycemia. Take steps to raise your glucose with fast-acting carbohydrates.

3. Alert others around you. Tell someone from your support team that your glucose is low.

What are considered ‘normal’ blood sugar levels?

Normal blood glucose levels are typically less than 100 mg/dL before a meal and less than 140 mg/dL 2 hours after a meal. But for someone with diabetes, what’s ‘normal’ or desirable is different. And often, it’s also different for many other people with diabetes. 

As a general rule, the American Diabetes Association (ADA) recommends the following blood glucose targets for people with diabetes:

If you have diabetes, your care team will give you personalized glucose and hemoglobin A1C goals. Keeping a close eye on your blood glucose levels at home with a glucometer or by wearing a CGM will help give your diabetes care team the information they need to help you make changes to your treatment. By looking at your personal glucose data, they’ll be able to offer ongoing advice to help you reach and stay within these goals — without overshooting or undershooting them too often. 

You’ll most likely also get a blood test called hemoglobin A1C every few months. This test measures your average blood glucose over the last 2 to 3 months. It paints a pretty accurate picture of how your diabetes treatment is working over time. 

The ADA recommends people with diabetes target an A1C of 7% and lower. But again, that may be different for each person. For example, your healthcare provider may suggest you aim for a higher A1C if you’re an older adult with multiple medical problems or memory issues. If you’re pregnant, they may suggest a lower A1C target.

What causes low blood sugar in people with diabetes?

 Now that you know what hypoglycemia is, it’s helpful to understand what causes it, too. While there are a lot of triggers for hypoglycemia, the most common causes for people living with diabetes include:

• Exercise

• Diabetes medications, like insulin or oral medications that raise insulin production, such as sulfonylureas or glinides

• Illness

• Skipped meals

• Alcohol

The best way to understand what affects your blood glucose is through personal experience. By collecting data (with a glucometer or CGM) and spotting patterns, you’ll begin to understand what happens in your body. You’ll then learn to predict which situations and events will drive your blood glucose levels down — and take steps to prevent it.

What can cause a sudden drop in my blood sugar levels?

Many factors can affect your blood glucose levels — and sometimes, there’s a combination of factors. 

In general, sudden drops in glucose are from:

• Giving too much medication (insulin) for the number of carbohydrates eaten 

• Exercising (both during and after exercise)

• Scheduling changes to mealtimes or medication times

• Skipping meals

You can prevent sudden drops in glucose by sticking to a regular medication and eating schedule, counting carbohydrates, and closely following your diabetes care plan. Your provider can recommend some changes if that’s not doing the trick. 

For some people who feel like their blood glucose is dropping quickly, it’s because they are missing the early warning signs of hypoglycemia. This is known as “hypoglycemia unawareness.” It’s a problem because missing early warning signs can lead to more serious symptoms. If you haven't already, be sure to let your provider know if you’re having this problem.

Best ways to prevent low blood sugar if you have diabetes

While you might not be able to prevent hypoglycemia all of the time, you can lower how often you have it. By checking your blood sugar regularly with a glucometer or wearing a CGM, you’ll be more aware of glucose changes. A CGM can be helpful in preventing low glucose, especially overnight or during exercise.

Let your diabetes care team know if you spot any glucose patterns. They’ll look at your data and can help you make suggested changes to your: 

• Diabetes medications

• Exercise plan

• Diet

Low blood sugar without diabetes, or non-diabetic hypoglycemia, is very rare. So if hypoglycemia occurs in an otherwise healthy person, it may be a sign that something else is going on. You may need to find out what that is, so be sure to let your healthcare provider know.

How can you treat low blood sugar quickly?

The treatment strategy for hypoglycemia is the same for everyone with diabetes. If you’re feeling symptoms of hypoglycemia, use a glucometer to check your blood glucose or look at your CGM. If you’re hypoglycemic, have fast-acting carbohydrates right away. They can usually fix the problem. 

The “15-15 rule” is an easy way to remember how to quickly treat a low blood sugar level that’s between 55 to 69 mg/dl: 

• Take 15 grams of fast-acting carbohydrates.

• Wait 15 minutes.

After 15 minutes, check your sugar level again. If you’re still below 70 mg/dl, repeat the cycle.

Some examples of fast-acting sugar sources that you can carry with you at all times include:

• 4 glucose tablets

• 1 tube of glucose gel

• ½ cup of fruit juice or regular soda

• 6 large jellybeans

• 1 tbsp of sugar or honey

Glucose below 55 mg/dl is more serious and may mean you need help. Teach others to call 911 if you:

• Don’t respond to fast-acting sugars

• Can’t eat or drink

• Have confusion or trouble talking or walking

• Pass out or have a seizure

If you’ve been prescribed glucagon, an emergency medication that you can inhale or inject to raise your blood sugars, make sure your helpers know where it is and how to use it. The best way to avoid an emergency is to have a plan in place.

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Written by:

Jewels Doskicz, RN, BA

Jewels Doskicz, RN, BA, is an Arizona-based registered nurse with 22 years of hospital-wide clinical nursing experience and 11 years of medical writing and editing experience. She was a former healthcare content creator for a digital health tool at HealthLoop and director of clinical content operations at GetWellNetwork.

Edited by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. An experienced and dedicated pulmonologist and hospitalist, she spent a decade practicing and teaching clinical medicine at academic hospitals throughout London before transitioning to a career in health education and health technology.

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