Causes of Low Blood Sugar Without Diabetes

Medically Reviewed By Alana Biggers, M.D., MPH

Several factors can cause low blood sugar, including fasting, gastric bypass, reactive hypoglycemia, and other medical conditions. According to the Centers for Disease Control and Prevention (CDC), Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source severe hypoglycemia occurs when blood sugar levels drop below 54 milligrams per deciliter (mg/dL). If left untreated, these low blood sugar levels can be life threatening. Treatments will focus on returning blood sugar to a safe level.

Read on to learn more about which factors, other than diabetes, can cause low blood sugar and which symptoms to look for.

Reactive hypoglycemia

there are empty plates on a table
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If you notice symptoms of hypoglycemia after eating a meal, typically within 2 to 5 hours Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source , this could be a condition called reactive hypoglycemia, or postprandial hypoglycemia.

The actual cause of reactive hypoglycemia is not known. However, some scientists think it may happen when your pancreas produces too much insulin after a meal that’s high in carbohydrates.

Symptoms you experience can also relate to a particular food, alcohol, or certain surgical procedures.

Most often, there are no underlying causes for reactive hypoglycemia. However, some known risk factors include:

  • Prediabetes: This is the early stage of diabetes. During this period, your body may not produce the proper amount of insulin.
  • Enzyme deficiencies: While rare, having a deficiency in a particular enzyme, called PEPCK, can lead to episodes of hypoglycemia after meals.

It can help to keep a food diary. This will help your healthcare professional pinpoint any foods that could be affecting your blood sugar.

Fasting hypoglycemia

Fasting hypoglycemia is also called unreactive hypoglycemia.

You can experience low blood sugar if your body does not have enough glucose. This is because your body is not processing food effectively. Food, and therefore glucose, is your body’s primary source of energy.

However, there are different causes of fasting hypoglycemia, other than simply not eating enough. These include:

  • certain medications
  • alcohol (binge-drinking can lower glucose levels)
  • exercise
  • medical conditions, such as hypothyroidism
  • eating disorders, such as anorexia
  • stomach surgery
  • tumors, such as on your pancreas, which will affect insulin levels

Gastric bypass

Gastric bypass surgeries can help if you have type 2 diabetes because they can improve glucose control. Undergoing weight loss surgery, known as bariatric surgery or a gastric bypass, can increase your risk of experiencing hypoglycemia, according to 2022 research Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source .

This is the result of changes to your metabolism, which cause your body to produce too much insulin after a meal, leading certain cells in your pancreas to develop an increased sensitivity to glucose, the Endocrine Society explains. This can also develop after exercise.

However, less than 10% of people go on to develop hypoglycemia after surgery. It is not yet known why some people who undergo weight loss surgery experience hypoglycemia and others do not. More research is needed to determine the cause so that post-operative treatment plans can be more specific for individuals.

Some methods recommended for managing this form of hypoglycemia include:

  • Dietary modifications: This involves lowering your intake of simple carbohydrates, such as white bread, and increasing your intake of protein.
  • Medications: One example is acarbose, which has been successful in treating hypoglycemia that develops after gastric bypass surgery, 2019 research Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source suggests.
  • Surgical procedures: In severe cases, doctors may recommend gastric bypass removal.

If you have recently had weight loss surgery and experience symptoms of hypoglycemia, seek advice from your healthcare professional as soon as possible.

Other medical conditions

Aside from diabetes, a number of health conditions may cause hypoglycemia, per 2022 research Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source . These are typically conditions that interfere with your hormonal system, called your endocrine system. This is because insulin, the substance that regulates blood sugar, is a hormone.

Some of these conditions include:

  • Hepatitis: Hepatitis is an inflammatory condition that affects your liver. If the liver cannot produce enough glucose from what you are consuming, it can lead to hypoglycemia.
  • Pituitary disorders: The pituitary gland is responsible for regulating vital bodily functions. An issue with this gland can lead to hypoglycemia because it may interfere with insulin regulation.
  • Kidney concerns: Your kidneys help your body process medication and get rid of waste products. If your kidneys are not functioning as they should, a buildup of waste products can change your blood sugar levels.

Medications

If you take medication for diabetes but you do not have diabetes, you are likely to experience hypoglycemia.

Hypoglycemia can be the side effect of a variety of medications. Such as:

  • Malaria medication, or quinine: This medication has been proven to cause a large release of insulin, which can cause hypoglycemia, according to a 2017 research review Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source .
  • Antibiotics: Examples include cefditoren Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source and tigecycline, which can lead to hypoglycemia in some people. These can treat conditions such as pneumonia.
  • Beta-blockers: These medications, which can treat heart conditions, are associated with an increased risk of hypoglycemia.

When to contact a doctor

Dietary changes can usually help you manage your symptoms. However, if you are experiencing hypoglycemia after a surgical procedure or as a result of medication, you should seek advice from your healthcare professional.

They will be able to check you for any other health conditions that may be causing your symptoms.

Learn about warning signs of low blood sugar.

Treatment for low blood sugar

Most cases of hypoglycemia do not require medical attention. If you experience hypoglycemia, a short-term fix is to eat 15 grams of a carbohydrate, wait 15 minutes, and eat another 15 grams if needed, as suggested by 2014 research Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source .

Other options include taking a glucose tablet or drinking fruit juice.

Learn more about what to eat when you have low blood sugar.

Complications

If your blood glucose regularly goes below standard levels without treatment, you may risk the following complications, according to 2022 research Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source :

Untreated hypoglycemia can also lead to death, which is why it’s important to talk with a healthcare professional about symptoms, treatment, and prevention.

Preventing low blood sugar

For people with more frequent episodes of low blood sugar, the following long-term dietary changes can help prevent episodes:

  • eating smaller, more frequent meals
  • avoiding foods high in sugar
  • limiting alcohol intake
  • avoiding caffeine
  • eating a balanced diet of proteins, carbohydrates, and healthy fats

Summary

While hypoglycemia is more common if you have diabetes, it can happen in people without diabetes, too. It can result from a variety of factors, from fasting to surgery to medications.

In most cases, treatment involves the consumption of carbohydrates. Low blood sugar and its complications are usually preventable through dietary changes.

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  11. Pituitary gland. (2021). https://www.yourhormones.info/glands/pituitary-gland/
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Medical Reviewer: Alana Biggers, M.D., MPH
Last Review Date: 2022 Oct 28
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