What is reactive hypoglycemia and how do I treat it?
If you’re feeling shaky, sweaty, light-headed or suddenly hungry a few hours after eating you could be experiencing reactive hypoglycemia, a drop in blood sugar that happens after a meal. While it is not always dangerous, it can be uncomfortable and may be a sign that you need to take a closer look at your food choices, meal timing and/or diabetes treatment plan. Here is more information on how to recognize reactive hypoglycemia and what you can do to alleviate symptoms.
Article highlights
- Understand why blood sugar can drop a few hours after eating
- Recognize the symptoms of reactive hypoglycemia
- Learn how to treat a low blood sugar episode safely
- Find practical ways to help prevent reactive hypoglycemia from happening again
What is reactive hypoglycemia, and how is it different from other low blood sugar episodes?
Hypoglycemia occurs when your blood sugar drops below a healthy level (under 4 mmol/L). Reactive hypoglycemia, also known as postprandial hypoglycemia, is a type of low blood sugar that develops after eating, typically within two to four hours (and occasionally up to five hours) after a meal.
Unlike hypoglycemia caused by taking too much insulin, skipping meals, exercising more than usual or drinking alcohol, reactive hypoglycemia is triggered by the body’s response to food. After a meal—particularly one high in carbohydrates—the body may produce more insulin than necessary. This excess insulin can cause blood sugar levels to drop lower than normal a few hours later.
What causes reactive hypoglycemia in people with diabetes?
Reactive hypoglycemia can happen when the timing or amount of insulin or certain diabetes medications does not match the food eaten. It may also occur after meals that are high in quickly digested carbohydrates, such as sugary drinks, sweets or refined grains.
While the exact cause of reactive hypoglycemia is not always clear, experts note that it may be related to excess insulin release after a meal, changes in digestion, or—less commonly—other medical conditions. Interestingly, the condition is common in people with and without diabetes and is more prevalent in those who are overweight or have had gastric bypass surgery.
What are signs and symptoms of reactive hypoglycemia?
Symptoms can vary from person to person, but may include:
- feeling hungry soon after a meal
- shakiness
- sweating
- feeling anxious
- feeling weak or light-headed
- confusion
- extremely fatigue
- irritability
- blurry vision
- a racing heart
- headaches
Be sure to check your blood sugar when any of these symptoms occur. Some people can feel symptoms that resemble low blood sugar even when their glucose level is not actually low. Knowing your number can help you and your healthcare team understand what is really happening.
How do I treat reactive hypoglycemia?
If your blood sugar is low, the latest guidelines from Diabetes Canada recommend treating mild-to-moderate hypoglycemia with 15 grams of fast-acting carbohydrate.
Some examples include: 4 glucose tablets, 5 cubes of sugar, 150ml of full-sugar juice, 6 Life SaversTM or 1 tablespoon of honey.
After 15 minutes, recheck your blood sugar. If it is still low, treat again. If your next meal is more than an hour away, a snack that includes carbohydrate and protein can help keep blood sugar stable.
If someone is confused, unconscious or unable to swallow, seek medical attention right away.
Click HERE to access a printable Hypoglycemia Quick Card resource.
How do you prevent reactive hypoglycemia?
Preventing reactive hypoglycemia starts with incorporating steadier eating patterns and regular exercise into your routine. Try:
- eating smaller meals more often
- spacing meals about three to four hours apart
- including protein with every meal and snack, and
- not skipping meals.
Be sure to limit alcohol, as well as sugary foods and drinks, including pop, juice, candy, cakes and cookies. These can raise blood sugar quickly but also contribute to a sharp insulin response and a later drop.
Instead, choose meals and snacks that combine complex carbohydrates with protein. Some good examples include whole grain crackers with cheese, pita with hummus, Greek yogurt with nuts, or toast with peanut butter. Fibre-rich foods such as whole grains, vegetables, fruit, beans and lentils can also help slow digestion and support steadier blood sugar levels.
This recipe for Frozen Berry Parfait is great for a high-protein breakfast or snack. For a healthy lunch or dinner that will help keep your blood sugar levels in check try this Grilled Fish Sandwich with Spicy Mango Slaw and Yogurt Sauce.
When should I talk to my healthcare provider about reactive hypoglycemia?
If you have repeated symptoms after meals, blood sugar readings below your target range, episodes that are hard to predict, or lows that happen while driving, exercising, working or sleeping, it’s time to talk to your doctor or someone from your diabetes care team.
It’s also important to seek medical advice if you have had stomach or intestinal surgery, if symptoms are becoming more frequent, or if you are taking insulin or medications that can cause hypoglycemia. Your care team will review your medications, meal timing, blood sugar records and activity patterns to help identify what is triggering these episodes.
Your 3-step action plan to manage reactive hypoglycemia
Step 1: Document what’s happening
When symptoms occur, check your blood sugar if possible. Write down the reading, what you ate, when symptoms started and how you treated it.
Step 2: Treat the low safely
Use 15 grams of fast-acting carbohydrate if your blood sugar is low, then recheck after 15 minutes. Avoid overtreating, as this can lead to a rebound high.
Step 3: Look for patterns
Bring your notes to your appointment with the doctor or other diabetes care team professional. Together, you can look for patterns in meal timing, food choices, medications and activity.
Although reactive hypoglycemia can be frustrating, it is very manageable. Paying attention to when symptoms happen, choosing balanced meals and snacks, and working with your diabetes care team can help you reduce episodes and help you keep on top of managing your diabetes optimally.
