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What Is Hypoglycemia?

Causes, symptoms, diagnosis, treatments, and support

With Elena Christofides and Jennifer Shine Dyer MD, MPH

When you’re diabetic, a severe drop in blood sugar can strike even when you’re doing everything right. Glucose is your body’s main source of energy and fuels your brain, so it’s critical to recognize the early signs of an episode before it becomes severe enough to cause you to pass out or worse. We’re here to empower you with clear answers to all your pressing Qs.

Definition Causes | Symptoms | Diagnosis | Treatments | Complications Fast Facts | Support 

What is hypoglycemia?

Hypoglycemia is the medical term for low blood sugar, or glucose. Sounds simple enough, right? Well, the condition can be surprisingly difficult to diagnose and manage. Despite the fact that low blood sugar is most commonly associated with diabetes, you don’t have to be diabetic to experience episodes of hypoglycemia. Learning how to spot and treat it yourself before it progresses to an emergency is the most important step to prevent complications.

Hypoglycemia Fast FactsInfographic by Lauren Hunter

What are the signs and symptoms of hypoglycemia?

Hypoglycemia tends to present as a cluster of symptoms, and they often occur together. The most common signs of dangerously low blood sugar include:

  • Dizziness, disorientation, light-headedness, and an inability to think clearly
  • Hunger, especially if you’ve just eaten
  • Heightened irritability, confusion, and anxiety
  • Clamminess and sweating, with cold hands and feet
  • Drastic mood swings

Signs and symptoms of HypoglycemiaIf you have one or more of these symptoms contact your doctor.

What causes hypoglycemia?

If you have diabetes, there are common triggers to avoid. If you’re diabetic and experience any of the above low blood sugar symptoms after any the following behaviors, it’s important to alert your physician to see whether you have dangerously low blood sugar.

  • Too few carbohydrates. As carbohydrates are your body’s main source of glucose, not having enough of them can cause a drop in blood sugar.
  • Skipping meals. Just like consuming too few carbohydrates, skipping meals can prevent your body from receiving the energy it needs from glucose.
  • Strenuous physical activity. Exercising more than usual, especially if you haven't eaten enough carbohydrates at a meal, can cause a hypoglycemic episode.
  • Excessive drinking. Alcohol can interfere with your body’s ability to metabolize glucose.
  • Not eating soon enough after insulin treatment. If you take insulin as prescribed during mealtimes, but delay eating, this can cause hypoglycemia.
  • Too much insulin. If you take too much insulin, this can cause your blood sugar to crash.

How is hypoglycemia diagnosed?

Hypoglycemia displays differently from person to person. Glucose maintenance is like a thermostat and may require adjustment based on how you’re feeling. A blood glucose reading will determine whether you’re experiencing hypoglycemia, and your doctor can recommend a home blood glucose meter to self-monitor your own blood sugar levels.

Low blood sugar is typically defined as 70 milligrams per deciliter, though it varies depending on your body composition. Dangerous levels of low blood sugar are anything below that. Getting into the habit of monitoring your own blood sugar levels with the help of your doctor is the first step in diagnosing and managing your hypoglycemia.

“If a person is acting a bit goofy or boisterous (often described as seeming “drunk” while perfectly sober) but they deny symptoms of hypoglycemia, then ask them to check their blood glucose level with a blood glucose monitor,” explains diabetes specialist David Klonoff MD. “The result might be surprisingly low. In that case, the person can be rescued with oral sugar before their condition worsens to where they are at risk of brain damage associated with going into a hypoglycemic coma.”

Management means that fine line diabetes patients walk between normal blood sugar and abnormal blood sugar,” explains Dr. Elena Christofides. “Simple avoidance of hypoglycemic episodes isn’t the correct way to think about it. The most important thing that people need to appreciate is that avoidance of hypoglycemia by maintaining their blood sugar artificially high is not saving them, as high blood sugar presents its own risks.”

If you frequently have low glucose levels, it’s important to work with your physician in order to determine root causes rather than just raising your blood sugar, which, as Dr. Christofides explains, can exacerbate risks of diabetic complications. Remember, even though hypoglycemic episodes increase anxiety and can cause symptoms like spiking blood pressure and a racing heart, the condition is usually not life-threatening. An episode is sometimes referred to as a hypoglycemic attack, but nothing's actually attacking your body—it's just alerting you to what it needs (more glucose in your blood).

“Most people are afraid they're going to die because they have a single episode of hypoglycemia, which simply isn’t true,” says Dr. Christofides.

What are the treatments for hypoglycemia?

Make an appointment with an endocrinologist if you feel like you’re having episodes of hypoglycemia, even if you’re not diabetic. They’ll talk you through treatment strategies, including:

  • Adjusting your medications. You may need to change how often you take insulin or other medications, which medications you’re on, how much you take, and when you take them.
  • Working with a registered dietitian on a personalized meal plan that stabilizes blood sugar levels. There’s no one-size-fits-all hypoglycemia diet, but a nutritionist can help you figure out a consistent meal plan tailored to you, and teach you how to count carbohydrate grams to go along with your health and routine.
  • Increasing and improving self-monitoring of your blood glucose levels. Knowing your blood glucose level throughout the day—when you get up, before meals, and after meals etc.—can help you keep it from getting too low.
  • Limiting consumption of alcoholic beverages. Alcohol interferes with the way your body metabolizes glucose. If you're prone to hypoglycemia, consider decreasing how much alcohol you consume.
  • Glucose tablets (dextrose). Make sure you always have glucose tablets on hand, whether at home, school, the office, or the gym. After taking the tablet, check your blood sugar. If it’s still low, take another tablet. If that doesn’t help, check with your doctor.

How can I stop my blood sugar from crashing?

 Here are a few ways to avoid hypoglycemic episodes:

  • Get in the habit of self-monitoring your blood glucose. Keeping track of when your blood sugar drops can help you recognize aspects of your routine that may be contributing to your hypoglycemia. Dr. Klonoff recommends a continuous glucose monitor. “It’s the best tool for automatically checking your blood glucose levels around the clock,” he says.
  • Change your meal plan. When, what, how much, and how often you eat all play a big part in your blood glucose levels. A dietitian can teach you about healthy, well-balanced food choices that will make it easier for you to maintain an acceptable blood sugar range.
  • Keep a stash of glucose tablets on hand. With your doctor's recommendation, make sure you always have glucose tablets with you. You can stick them in your briefcase, purse, car, desk, school locker, etc. You may also want to keep snacks nearby—for example, cheese or peanut butter crackers, although doctors suggest over-the-counter glucose tablets for more accurate dosage. “Do not eat a ‘healthy’ sugar-free candy bar during hypoglycemia,” warns Dr. Klonoff. “Its lack of sugar means that it will not raise your blood glucose level sufficiently when you want it to.”
  • Certain drinks can help get your blood sugar up as well. Try 8 oz. of fruit juice, a soft drink (not sugar-free), or a cup of milk.

What complications can be caused by hypoglycemia?

Passing out from low blood sugar because you have not recognized the early signs and symptoms is called hypoglycemia unawareness, and can be quite dangerous depending on where you are, explains Dr. Klonoff. As doctors are required to report such incidents to the Department of Motor Vehicles, it can also mean a suspended driver’s license.

If this is something you’re worried about, “Wearing a continuous glucose monitor with an alarm for hypoglycemia can alert a person who is prone to developing low blood sugar levels that their blood glucose concentration is becoming dangerously low, so appropriate preventive action can be taken before they lose consciousness,” explains Dr. Klonoff.

What if I’m experiencing hypoglycemic episodes even though my doctor has confirmed that I’m not diabetic or prediabetic?

If you have low blood sugar and don’t have diabetes or prediabetes, it can be a sign of another serious health issue such as a tumor, hormone deficiency, kidney disorder, anorexia, or other eating disorder, all of which can cause dangerously low blood sugar.

Anorexia has the highest mortality of any psychiatric disorder, and the cause of death can be hypoglycemia, so take your illness seriously and seek help if you suspect your eating disorder may be progressing to the point where it is causing you to faint or experience other signs and symptoms of dangerously low blood sugar. The National Eating Disorders Association (NEDA) has resources on how to identify the signs that you may have an eating disorder, a hotline for help, as well as easily accessible information on everything from how to know when you need help to how to find quality treatment options in your zip code.

“People who are not diabetic don't spontaneously have hypoglycemia for no reason,” explains Dr. Christofides. “It’s often an indication of another underlying issue, such as a hormone deficiency or eating disorder, so it’s important to schedule an appointment with your doctor to determine the cause in order to prevent complications.”

Common causes of hypoglycemia in people without diabetes include:

  • Pancreatic tumor
  • Medication that inhibits the proper production of insulin
  • Hepatitis or kidney disorders
  • Hormone deficiencies
  • Anorexia and other eating disorders

Work with your doctor to find out what’s triggering your low blood sugar levels in order to come up with the right treatment plan for the root cause of your hypoglycemia.

What extreme conditions can occur if hypoglycemia is left untreated?

Although severe episodes (you may have heard the terms “diabetic shock,” “hypoglycemic shock” or “insulin shock”) which can trigger potentially life-threatening comas are rare, they require immediate emergency room care, so it’s best to make sure you are tracking your blood sugar so that you never have to worry about getting to that point. A drop in blood sugar means less fuel for your brain, so it’s critical for your body to receive enough glucose. “Hypoglycemia that leads to extended, reduced brain function is the biggest concern, as this can lead to seizures and loss of basic bodily functions controlled by the brain, which can ultimately lead to death,” explains Dr. Dyer.

Where can I find support?

The Hypoglycemia Support Foundation, established nearly 40 years ago, is a national group that offers many resources, including advocacy. They offer salons so that you can personally connect with people like you who are also dealing with bouts of low blood sugar.

Occasionally blood sugar crashes are so extreme they require emergency room care for an immediate dextrose IV treatment. If you have diabetes, wear a medical bracelet that does TK thing? What will this bracelet have on it? A number of one of your contacts? Can you answer and smooth out with this line? have a circle of people who serve as close contacts and are aware of your condition and how to help.

FAQ: Frequently Asked Questions

Who is most at risk for hypoglycemia?
Aside from diabetics, Dr. Jennifer Shine Dyer notes that children are more prone to
experience episodes of hypoglycemia because of their smaller body size, as well as having less fat to burn to maintain energy when glucose levels are low. “Eating meals every 4 to 6 hours should maintain glucose levels if this is the only cause of hypoglycemia,” she says.

How do I know it's low blood sugar?  
To know if you're suffering from hypoglycemia, you'll need to begin tracking your glucose levels under the supervision of your doctor. Drugstores and pharmacies carry test strips, as well as glucose meters, which will help. You can even see the effect that different foods have on your body by checking your blood sugar after eating.

Does fasting affect my blood sugar levels? 
Yes, going without food can trigger hypoglycemia. If you have diabetes and are concerned about hypoglycemia, aim to eat smaller, more frequent meals and snacks that are low in processed sugars every three hours or so.

Does alcohol consumption trigger low blood sugar?
Excessive alcohol consumption, defined as more than one drink per day for women and more than two drinks per day for men, especially with little food, can keep your liver from releasing glucose, which can lead to hypoglycemia.

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Hypoglycemia Symptoms