Do You Have Reactive Hypoglycemia?

BY AMY CAMPBELL, MS, RD, LDN, CDCES | APRIL 6, 2023

If you have diabetes and take insulin or certain types of diabetes pills, such as sulfonylureas or meglitinides, you are at risk for having hypoglycemia. Hypoglycemia means low blood glucose (sugar) and this occurs when the level of glucose in your blood drops below a safe level. If you have diabetes, this level is typically a blood sugar reading below 70 milligrams per deciliter (mg/dl), although the number can be different for some people.

While hypoglycemia is most common in people who have diabetes, it can occur in people who do not have this condition. This is called nondiabetic hypoglycemia and there are two types of hypoglycemia in this category. Learn more about one type of nondiabetic hypoglycemia, including causes, symptoms, and how it’s treated.

Reactive hypoglycemia

One type of nondiabetic hypoglycemia is called reactive hypoglycemia. Also called postprandial hypoglycemia, this is hypoglycemia that happens after eating, usually within two to four hours. Reactive hypoglycemia can occur in people with and without diabetes.

Symptoms of reactive hypoglycemia include:

• Feeling dizzy
• Feeling shaky
• Rapid heartbeat
• Anxiety
• Sweating
• Weakness
• Nausea
• Hunger
• Confusion
• Irritability

If you have an episode of reactive hypoglycemia, the fastest way to bring your blood sugar back up is to eat or drink something that contains carbohydrate (note: these are the same items that people with diabetes used to treat low blood sugar). Good choices are:

• 4 ounces of fruit juice
• 4 ounces of regular (not diet) soda
• 1 tablespoon of sugar or honey
• 3 to 4 glucose tablets
• 8 ounces of skim milk
• 1/2 banana

Causes of reactive hypoglycemia

Causes of reactive hypoglycemia aren’t always clear. But certain factors may contribute to this condition, such as:

• Eating a high-carbohydrate meal (especially carbs that are refined or high in sugar), which results in too much insulin released from the pancreas.
• Gastrointestinal surgery, such as gastric bypass surgery for weight loss or an ulcer, or surgery to treat gastroesophageal reflux. Stomach surgery may cause food to pass into the intestines too quickly.
• Prediabetes, which can make it hard for the pancreas to make the right amount of insulin at the right time.
• Alcohol, for some people. It can increase the insulin response to a meal that contains carbohydrate, and it also can limit or prevent the liver from releasing glucose in the blood to help sustain or raise blood sugar.
• A tumor in the pancreas called an insulinoma. This type of rare, noncancerous tumor causes the pancreas to make extra insulin, which leads to a drop in blood sugar.
• Rare enzyme deficiencies that make it hard for the body to break down food.

Since the above symptoms can occur due to other medical conditions, it’s important to see your health care provider for a proper diagnosis. If reactive hypoglycemia is suspected, your provider may order some tests that could include measuring a fasting blood glucose level. Another test that you might have is called a mixed meal tolerance test (MMT). This test looks at how much insulin the pancreas makes after drinking a liquid meal that contains carbohydrate, protein, and fat. In preparation for a MMT, you need to fast for at least 8 hours. An IV line will be inserted in a vein in your arm, and then you will be given the liquid meal to drink. Once you drink the liquid meal, your blood will be drawn through an IV line every 30 minutes for two hours.

Treating reactive hypoglycemia

Treatment of reactive hypoglycemia usually involves making some lifestyle changes. These include:

• Eating several small meals during the day, as well as some snacks to help prevent hypoglycemia, and not going longer than three hours without eating.
• Limiting refined carbs, such as white bread, white pasta, and white rice, as well as high-sugar foods, such as sweetened drinks, table sugar, honey, maple syrup, candy, and desserts.
• Choosing unrefined, whole-grain/high-fiber carbs, such as oatmeal, brown rice, quinoa, whole-grain breads, and legumes.
• Aiming for a balance or mix of carbohydrate, protein, and fat at meals. An example of a mixed meal might be steel cut oatmeal topped with some nuts or with an egg on the side.
• Eating food when you drink alcohol.
• Limiting caffeine. Some people find that consuming beverages or foods that contain caffeine can trigger reactive hypoglycemia.
• Doing some type of physical activity on a regular basis.

Some research indicates that medicines used to treat diabetes, such as metformin, glitazones, and alpha-glucosidase inhibitors can also be helpful in treating reactive hypoglycemia. Talk with your provider about other treatment options if you find that lifestyle changes are not helping.