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 (sugar). This happens when your blood glucose is less than 70 mg/dL. A glucometer (blood glucose meter) is one of the best ways to see 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, feeling hungry, a fast heartbeat, and feeling anxious. While hypoglycemia can feel different for each person, mild to moderate low blood sugar can usually be treated with fast-acting sugar.

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 level of glucose in your blood drops below 70 mg/dL. Glucose is a main source of energy for your body’s cells, so when it’s low, 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. Managing diabetes means constantly balancing medications, food, exercise, and other factors. Because of this, blood glucose is always changing and can be hard to keep within the target range.

Low blood sugar symptoms

If you have hypoglycemia, you might feel symptoms that are uncomfortable. These can be physical, like sweating and shaking. They can also affect your thinking or mood, like confusion or feeling nervous. Anyone with diabetes can get hypoglycemia, and symptoms can change from episode to episode. 

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Some signs and symptoms of hypoglycemia include: 

• Hunger

• Fast heartbeat

• Shakiness

• Anxiety

• Irritability

• Sweating

• Tingling

• Dizziness

• Weakness

• Drowsiness

• Confusion

• Fainting or passing out

What causes low blood sugar in people with diabetes?

It’s helpful to understand what causes hypoglycemia so you can avoid it as much as possible. While there are a lot of triggers for hypoglycemia, the most common causes for people living with diabetes include:

• Injecting too much of the wrong kind of insulin 

• Taking oral medications that raise insulin production, like sulfonylureas or glinides

• Illness

• Exercise (both during and after)

• Skipping or delaying meals

• Consuming alcohol

The best way to understand what affects your blood glucose is through personal experience. Using a glucometer or a CGM can help you collect data and spot patterns. This helps you understand what causes your blood sugar to drop so you can prepare and prevent it.

If you notice your blood glucose is dropping quickly, it’s possible you’re 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 this is happening to you, be sure to let your care team know you’re having this problem.

How can you fix low blood sugar?

The treatment strategy for hypoglycemia is the same for everyone with diabetes. If you’re feeling symptoms of 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. Raise your glucose with fast-acting carbohydrates (more on this below).

3. Alert others around you. Tell a friend or family member that your glucose is low.

What you do next depends on your blood sugar level. The “15-15 rule” is an easy way to remember how to quickly treat a low blood sugar level that’s between 55 mg/dL and 69 mg/dL: 

• Take 15 g of fast-acting carbohydrates.

• Wait 15 minutes.

• After 15 minutes, check your blood sugar level again. If it’s still below 70 mg/dL, repeat the steps.

Some examples of fast-acting sugar sources 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 (not diet)

• 6 large jellybeans

• 1 tbsp of sugar or honey

A blood glucose level below 55 mg/dL is more serious. The best treatment is glucagon (or a glucagon-like medication), an emergency medication that you can inhale or inject to raise your blood sugar. If you’ve been prescribed a glucagon kit, 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.

You need help if your glucose is very low. Teach others to call 911 if you:

• Don’t respond to fast-acting sugar

• Can’t eat or drink

• Have confusion or trouble talking or walking

• Pass out or have a seizure

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 can be different. In fact, it can vary from person to person, even among those with diabetes.

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

• Before a meal (preprandial): 80-130 mg/dL

• 1-2 hours after beginning of the meal (postprandial): Less than 180 mg/dL

Note that these targets might be different for people who are older or pregnant. If you have diabetes, your care team will help you set personalized glucose and hemoglobin A1C goals.

Best ways to prevent low blood sugar if you have diabetes

You can prevent sudden drops in glucose by doing the following:

• Sticking to a regular medication and eating schedule

• Keeping a close eye on your blood glucose levels 

• Counting carbohydrates

• Following your diabetes care plan closely

While you might not be able to prevent hypoglycemia all of the time, you can reduce 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 patterns. They can look at your data and help you make changes to your medications, eating schedule, or exercise plan if needed.

Low blood sugar without diabetes — called non-diabetic hypoglycemia — is rare. If it happens to someone who doesn’t have diabetes, it may be a sign that something else is going on. It’s a good idea to get medical attention for this.

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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.

Reviewed by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined her interests in clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

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