If you’ve ever felt drunk—like, a little off-balance or unable to keep your thoughts straight—without drinking a drop of alcohol, you may have experienced hypoglycemia. That’s the official name for low blood sugar, which happens when the glucose in your blood falls below a certain level. It’s usually a quick fix, but in some circumstances, it can be serious, even life-threatening.

Overview

What Is Hypoglycemia?

Hypoglycemia is a condition where blood sugar (glucose) levels drop below normal. Here’s how it happens: Digestion breaks down most of the food you eat into a sugar known as glucose and sends it into your bloodstream as a source of energy. The influx of glucose signals your pancreas to produce insulin, which is a hormone that helps your body use the sugar. If the amount of glucose in your blood gets too low, you have hypoglycemia.

“You’ll often hear people say they have low blood sugar, but your body is actually well-designed to keep your blood sugar steady,” says New York-based Samantha Cassetty, R.D., a dietitian and co-author of the book Sugar Shock. You may feel sluggish or woozy until you eat or drink something, but most people aren’t in any real danger. “The exception is people with diabetes.”

With diabetes, people struggle to make enough insulin, or their bodies can’t use it well enough. Simply eating something may or may not balance your blood sugar if you have diabetes. Some diabetics may need to inject insulin or take certain medications to lower their blood sugar. To complicate matters more, if the dose doesn’t match the number of carbs they’re eating or their activity level, it can lead to hypoglycemia.

For people who have diabetes, the threshold for hypoglycemia is a blood glucose level lower than 70 milligrams per deciliter—normal range is 80-130 mg/dL. (If you take insulin, you should be familiar with these numbers, since you’re checking your blood sugar regularly.)

For those who don’t have diabetes, normal levels range from 55 to 140 mg/dL. Anything below 55 mg/dL would be considered hypoglycemia. But most of us only get our levels tested occasionally, at the doctor’s office, which means symptoms matter more than numbers here.

Symptoms

Low Blood Sugar Symptoms

Our bodies metabolize sugar at different rates, depending on numerous factors like what kind of sugar you’ve eaten, what else is already in your stomach, and how well you slept the night before. So signs of hypoglycemia vary from person to person.

Some early indicators—like these—can be mistaken for something else, or dismissed entirely:

  • Anxiety

  • Headache

  • Hunger or nausea

  • Irritability

“When my patients have undesirable events, it’s because they ignore these signs—and they’re easy to ignore,” says Betul Hatipoglu, M.D., director of the Diabetes and Obesity Center at University Hospitals in Cleveland, OH. “[If these early signs are disregarded], they’ll start to have a racing heart rate, or they might start to have shaking hands and sweating.”

Harder-to-ignore hypoglycemia symptoms include the ones Dr. Hatipoglu mentioned above, along with:

  • Blurred or impaired vision

  • Chills or clamminess

  • Difficulty concentrating

  • Fatigue or sleepiness

  • Feeling shaky or jittery

  • Lightheadedness or dizziness

  • Pale skin

  • Tingling or numbness in your lips, tongue, or cheeks

If you don’t catch those initial symptoms, hypoglycemia can progress and even become life-threatening. Some people with diabetes have what’s known as hypoglycemia unawareness—they don’t feel many symptoms, which puts them at risk for more severe cases. Signs of severe hypoglycemia include:

  • Confusion

  • Coordination problems

  • Not making sense

  • Feeling faint

  • Nightmares or crying out in your sleep

  • Not making sense

  • Seizures

Causes

What Causes Low Blood Sugar?

For people who don’t have diabetes, low blood sugar could occur for any of these reasons, per research in Endotext:

  • Alcohol consumption: Your liver plays an active role in how your body uses glucose, releasing it into your bloodstream between meals or while you sleep. The liver also metabolizes alcohol—and it’s not good at multitasking. Dealing with alcohol takes priority, so while that’s happening, your liver stops releasing glucose. If you haven’t eaten, your level can drop fast.

  • Certain medications: Some drugs affect your body’s insulin production, which can lead to hypoglycemia. Those include some antibiotics and antipsychotics, beta-blockers, and large quantities of non-steroidal anti-inflammatories.

  • Poor diet: When you eat simple carbs—foods made with added sugar and refined grains, fruit juices, and highly processed foods in general—your body turns them into glucose quickly, so your blood sugar spikes and falls.

  • Prolonged exercise: Your body needs extra energy when you work out, which means it uses more glucose. The longer you push yourself, the more likely you are to have your levels dip low.

Are You at Risk?

Who’s at Risk for Hypoglycemia?

The vast majority of serious cases happen in insulin-dependent people with diabetes—either type 1, which always requires it, or those who need insulin occasionally to help manage their type 2. The condition is less likely in people with type 2 who don’t use insulin.

Hypoglycemia in people with diabetes accounted for more than 200,000 ER visits in 2020, but people without diabetes rarely have dangerous cases.

In those milder instances of hypoglycemia, your blood sugar may be on the low side, but the situation usually turns around quickly—you aren’t at risk for serious complications, says Dr. Hatipoglu. In one study of non-critical hospital admissions, researchers found just 36 cases of non-diabetic hypoglycemia for every 10,000 patients.

But there are some groups that are more likely to have hypoglycemia without diabetes, including the following:

  • Alcoholics: Some experts say that 95% of alcoholics have chronically low blood sugar.

  • Bariatric surgery patients: Although it’s unclear why it happens, one in 10 people who have this weight-loss surgery experience low blood sugar a year or more after the procedure.

  • Older people: In a StatPearls study of non-critical hospitalizations, non-diabetic patients over the age of 65 were 50% more likely to have hypoglycemia.

  • People with underlying conditions: Some ailments increase your odds, including leukemia, sickle cell anemia, liver failure, congestive heart failure, and insulinoma, which involves rare, insulin-producing tumors

Types

Types of Hypoglycemia

For people with type 1 or type 2 diabetes, hypoglycemia is just… hypoglycemia. But when low blood sugar happens to someone who doesn’t have the disease, it falls into two types, according to the Endocrine Society.

Reactive Hypoglycemia

Reactive hypoglycemia happens when your blood sugar drops within four hours after you eat—usually a meal or snack high in carbohydrates. This can be a sign of prediabetes, when your body may have trouble making the right amount of insulin. It can also happen if you’ve had bariatric surgery.

Fasting Hypoglycemia

Fasting hypoglycemia is a condition where blood sugar levels drop to abnormally low levels after a period of not eating, typically overnight or between meals. This type of hypoglycemia can be caused by various factors, including certain medications, excessive alcohol consumption, hormonal deficiencies, or underlying health conditions like insulinomas (insulin-secreting tumors). Symptoms may include shakiness, sweating, confusion, irritability, and in severe cases, seizures or loss of consciousness. Managing fasting hypoglycemia often involves addressing the underlying cause and ensuring regular meals and snacks to maintain stable blood sugar levels.

Treatment

Treating Hypoglycemia

The easiest way to treat hypoglycemia is to eat a simple carbohydrate—something with sugar in it.

“Typically, that’s a half-cup of juice or a tablespoon of honey or maple syrup.” Cassetty says. “Make sure it’s the real thing—100% fruit juice, real honey or syrup.” These foods and beverages are all easy to consume and give your body a dose of sugar quickly. In a pinch, you could even drink half a can of regular soda, which would help thanks to its high sugar content. “Now is not the time for sugar-free,” says Cassetty.

For people with diabetes, the American Diabetes Association recommends a 15/15 approach to treating low blood sugar: Eat 15 grams of carbs and wait 15 minutes. Check your blood sugar, and if it’s still below 70 mg/dL, have another serving.

“It’s important [for people with diabetes] to be ready for it,” Dr. Hatipoglu says. “Pack glucose gels or a small juice box, so you don’t have to think about how many grams of carbs you’re getting.”

If you don’t have diabetes, you won’t have a way to test your levels—go by how you feel a quarter-hour after you eat sugar.

Prevention

Preventing Hypoglycemia

For people without diabetes, the best way to prevent hypoglycemia is to eat a healthy diet. That means choosing complex carbohydrates like whole grains, fruits and vegetables, and beans, rather than processed foods. Make sure you’re eating lean protein and healthy fats, too. All these options slow the digestive process, which helps to stabilize your blood sugar.

Beyond that, simply pay attention so you can figure out what triggers a drop in your blood sugar. For example, if you feel wobbly at the end of an intense workout, make sure to eat a snack before you hit the gym next time.

If you do have diabetes, Dr. Hatipoglu stresses the value of wearing a continuous glucose monitor, which helps you ward off hypoglycemia before it can hit. The wearable device keeps track of your blood sugar in real time, so you don’t have to prick your finger and test your blood every time. “The algorithm within the device is programmed so it can predict the patient is going to be low in 15 minutes,” she says.

Working With Your Doctor

Talking With Your Doctor About Hypoglycemia

An occasional bit of wooziness after a tough workout shouldn’t worry you. But if you don’t have diabetes and regularly find yourself experiencing symptoms of hypoglycemia, it’s time to speak to your physician. It may indicate an underlying condition that needs attention.

And if you use insulin for diabetes, frequent bouts of hypoglycemia signal your dose—or your diet—needs an adjustment.

This article was originally published July 28, 2022 and most recently updated July 10, 2024.
© 2024 HealthCentral LLC. All rights reserved.
Rodrigo Barros, M.D., Ph.D., Endocrinologist:  

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