Low blood sugar symptoms in adults without diabetes

Non-diabetic hypoglycemia is when someone who does not have diabetes has low blood sugar. It is considered an uncommon or rare condition. Non-diabetic hypoglycemia is usually diagnosed based on symptoms, blood sugar levels, and how your symptoms respond when you eat sugar.

Non-diabetic hypoglycemia can be caused by a variety of factors, from medications, past surgeries, medical conditions, or certain eating patterns. Here’s what you should know if you’ve been struggling with the symptoms of non-diabetic hypoglycemia.

Underlying Causes of Non-Diabetic Hypoglycemia

Hypoglycemia can develop from a variety of underlying causes.

Medication

Medications are the most common cause of hypoglycemia. The medications that can cause hypoglycemia include:

• Beta blockers: Like atenolol
• Drugs that fight infection: Such as gatifloxacin, pentamidine, quinine, or trimethoprim-sulfamethoxazole
• Heart arrhythmia medications: Like quinidine and cibenzoline
• Indomethacin: A pain reliever
• Sulfonylureas
• Metformin or thiazolidinediones: When used with sulfonylureas

If you have a history of unexplained hypoglycemia, let your healthcare professional know. You may need to switch medications, adjust your eating habits, or monitor your symptoms more closely to prevent your sugars from going too low.

Alcohol Intake

Alcohol interferes with normal blood sugar regulation and can produce highs and lows that contribute to alcohol dependency for some people. Starting with dietary changes to maintain stable blood sugar levels can be helpful for those trying to cut back on alcohol. These include choosing foods with fiber, protein, and healthy fats.

Having a drink with a meal rather than on an empty stomach can help buffer some of alcohol’s effects on blood sugar. If you notice that you’re more sensitive to the effects of alcohol than others, you may be experiencing a hypoglycemic reaction.

Passing out or dozing off after a couple of drinks could indicate hypoglycemia, which may leave you more vulnerable to the hazards of drinking.

Underlying Illness

An underlying illness may contribute to low blood sugar levels. Renal failure (kidney disease) can cause hypoglycemia in multiple ways, including:

• Decreasing the kidney’s ability to clear insulin
• Reducing the process of renal gluconeogenesis
• Slowing down the metabolism of hypoglycemia-causing medications
• Stunting appetite, causing you to eat less and making it more difficult to maintain adequate glucose levels

Because the liver is also central to maintaining balanced glucose levels, any disruption of liver function such as liver disease, hepatitis, or liver cancer can cause spontaneous hypoglycemia. A genetic condition called glycogen storage disease produces an enlarged liver and hypoglycemia caused by the inability to break down glycogen for energy.

Hormonal Deficiency

Aside from insulin, various hormones impact glucose regulation. Growth hormone from the pituitary gland and cortisol from the adrenal glands help maintain balanced blood sugar levels. Adrenal disorders (such as Addison’s disease) or pituitary disorders can cause hypoglycemia due to a lack of these blood sugar-stabilizing hormones.

The hormonal shifts in hypothyroidism (low thyroid hormone levels) may also lead to low blood sugars. This effect is seen in both children and adults with hypothyroidism and should be monitored as part of a comprehensive treatment plan.

Overproduction of Insulin

A rare pancreatic tumor called an insulinoma may produce more insulin than the body needs, causing hypoglycemia. Doctors aren’t sure exactly what causes insulinomas to grow, but they don’t tend to spread to other parts of the body.

Women between the ages of 40 and 60 are most commonly affected by insulinomas. It can take a while to get a correct diagnosis, but your symptoms should resolve once an insulinoma is removed.

Insulin overproduction can also be a problem for people who have undergone recent bariatric surgery. Since the body is used to higher carbohydrate and food intakes, the small portions and high protein requirements of a post-surgery diet can take some getting used to.

Your body may still be releasing the amount of insulin used during your pre-surgery eating habits. Your healthcare professional should warn you if this is a potential side effect of your procedure and give you guidance on treating it at home.

Insulin Autoimmune Syndrome

Insulin autoimmune syndrome is a rare condition where the body creates antibodies that attack insulin. When insulin is under attack, it has to work extra hard to do its job of regulating blood sugar levels.

The syndrome typically develops in adulthood. The symptoms are what you would expect from low blood sugar (fatigue, lightheadedness, sweating, fainting). Long term, it may result in permanent damage to the pancreas, so getting an accurate diagnosis and treatment is vital.

Reactive Hypoglycemia

Reactive hypoglycemia (postprandial hypoglycemia) typically happens within a few hours of eating a meal and is caused by insulin overproduction. The cause of reactive hypoglycemia in most people isn’t clear, but it may be related to a specific food that you ate or in variations of the timing of the food moving through the digestive tract.

Treatment will depend on figuring out the underlying cause, such as a tumor or medication. Eating every three hours and choosing balanced meals with fiber and protein can help prevent blood sugar highs and lows. To raise low blood sugar quickly, a 15-gram serving of carbohydrates through hard candy, dried fruit, or juice can be a short-term solution.

When to See a Doctor

Early warning signs and symptoms of hypoglycemia include:

• Anxiety
• Dizziness
• Headache
• Hunger
• Inability to concentrate
• Irritability
• Shakiness
• Sweating

If you are experiencing these symptoms and suspect they could be related to your medications, reach out to your provider to see if an adjustment is needed. If you believe your symptoms are from poor food intake, try consuming complex carbohydrates more consistently to maintain normal blood sugar levels.

Doing an intense workout on an empty stomach can produce hypoglycemia that’s easy to fix. In this case, you can treat hypoglycemia at home with a sports drink or snack, and no further medical help is needed.

When left untreated, severe hypoglycemia can lead to intense symptoms, like jerky movements, inability to eat or drink, muscle weakness, slurred speech, blurry or double vision, seizures, or unconsciousness. For any of these symptoms, contact your healthcare professional immediately.

Since hypoglycemia can cause you to pass out, you should alert the people who you spend time with about your condition so they know what to do in an emergency. Let your coworkers, family, and friends know when they should call 911. You can also wear a medical alert bracelet that notifies others of your health concerns.

A Word From Verywell

Hypoglycemia is usually a symptom of another health problem or lifestyle imbalance that should be addressed. Paying attention to how your body feels and communicating with your healthcare professional will help ensure that your body runs at optimal capacity.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

1. Eckert-Norton M, Kirk S, eds. Non-diabetic hypoglycemia. J Clin Endocrinol & Metab. 2013;98(10):39A-40A. doi:10.1210/jc.2013-v98i10-39A

2. MedlinePlus. Drug-induced low blood sugar.

3. Hypoglycemia Support Foundation. Another tragic and unrecognized aspect of hypoglycemia – its connection to alcoholism.

4. Bansal N, Weinstock RS. Non-diabetic hypoglycemia. In: Feingold KR, Anawalt B, Boyce A, et al., eds. Endotext. MDText.com, Inc.

5. Association for Glycogen Storage Disease. Type I glycogen storage disease.

6. Mukherjee E, Carroll R, Matfin G. Endocrine and metabolic emergencies: hypoglycaemia. Ther Adv Endocrinol Metab. 2011;2(2):81-93. doi:10.1177/2042018811401644

7. Kalra S, Unnikrishnan AG, Sahay R. The hypoglycemic side of hypothyroidism. Indian J Endocrinol Metab. 2014;18(1):1-3. doi:10.4103/2230-8210.126517

8. John Hopkins Medicine. Insulinoma.

9. University of Michigan Medicine. Hypoglycemia (low blood sugar) in people without diabetes.

10. Genetic and Rare Diseases Information Center. Insulin autoimmune syndrome.

By Anastasia Climan, RDN, CD-N
Anastasia, RDN, CD-N, is a writer and award-winning healthy lifestyle coach who specializes in transforming complex medical concepts into accessible health content.

Thanks for your feedback!

What causes low blood sugar without diabetes?

How do you feel when your sugar is low?

How do you know if your blood sugar is low without diabetes?

What are three signs of someone who has low blood sugar?