What Is Hypoglycemia?

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Hypoglycemia, or low blood sugar, is a condition that occurs when the glucose level in your blood is too low. It's usually related to having diabetes, but it can be caused by other factors or conditions as well. Symptoms include shakiness, fast heartbeat, sweating, headache, and fatigue.

Because blood sugar is the primary source of your body's energy, being hypoglycemic can turn into a dangerous situation if you don't treat it right away.

Having hypoglycemia indicates that something else is going on in your body, similar to when you have a fever.

What Is Hypoglycemia?
Verywell / Emily Roberts

Hypoglycemia Symptoms

It can be more difficult to notice hypoglycemia symptoms under some circumstances, such as when you're sick, feeling tired, stressed out, exercising, or drinking alcohol. Symptoms of hypoglycemia include: 

  • Trembling or weakness
  • Fast heartbeat
  • Sweating
  • Headache
  • Fatigue or feeling sleepy
  • Pale skin
  • Anxiety or irritability
  • Talking or yelling when you're sleeping
  • A tingling feeling around your mouth
  • Hunger
  • Dizziness
  • Confusion
  • Double or blurred vision
  • Lack of coordination
  • Seeming as if you're intoxicated
  • Convulsions or unconsciousness

When it comes to emergency care, use these symptoms as a guideline, but also listen to your instincts. If you feel that something is wrong, it's never a bad idea to call your doctor or head to the emergency room anyway.


Hypoglycemia occurs when your blood sugar drops too low (usually below 70 mg/dl), although the tipping point can vary from person to person.

If you don't have diabetes, hypoglycemia can be caused by drinking too much alcohol, taking certain medications that lower blood sugar, a lack of enough hormones, certain illnesses such as polycystic ovary syndrome (PCOS) or severe hepatitis, or because your body is producing too little glucose.

In people with diabetes, it can be caused by not eating enough carbohydrates, not eating at all, during or after an exercise session, or by taking too much insulin or medication. Excess insulin will cause too much glucose to be pulled from the bloodstream and transported into cells via glucose transporters.

Glucose enters cells with help from insulin and glucose transporters.

Certain situations may also increase your risk of hyperglycemia if you have diabetes. These include:

  • Heat: It can lead to hypoglycemia in people with diabetes by speeding up metabolism.
  • Not eating right after your insulin injection: If you've taken a dose of insulin in preparation for a meal, but you eat later than you thought you would, you may become hypoglycemic.
  • Difficulty calculating your insulin needs: If you're over or underestimating your insulin needs, your risk of hypoglycemia increases.
  • Going to bed with low blood sugar: If your blood sugar at bedtime is less than 99 mg/dL, hypoglycemia may occur while you're sleeping. In order to prevent this, make sure that your blood sugar level is at least 140 mg/dL at bedtime.


Like a fever, hypoglycemia is a symptom of another problem. Diagnosing hypoglycemia is easy in that a simple blood test can tell if your blood sugar level is too low. However, if you don't have diabetes, your doctor will need to figure out what's causing your hypoglycemia or your hypoglycemia-like symptoms.

Your doctor will likely do some fasting blood tests to see how your blood sugar responds, as well as additional testing to figure out what's behind your symptoms.


If you have diabetes, hypoglycemia may be treated at home if your symptoms are not yet severe and your blood sugar has not fallen too low. If you don't have diabetes and you experience symptoms of hypoglycemia, you should see your doctor as soon as possible.

If you have diabetes and you begin to feel shaky, sweaty, dizzy, or confused, test your blood sugar if your meter is available. If it's less than 70mg/dL, treat it with fast-acting carbohydrates, such as three to four glucose tablets, 8 ounces of milk, 1 ounce of pretzels, a serving of jelly beans or hard candies as determined by the package, a small granola bar, half a banana, 2 tablespoons of raisins, 4 ounces of juice, or soda (not diet). Re-test in 15 minutes and repeat treatment if your blood sugar has not gone up.

If you don't have your meter but you can tell that your blood sugar is low, treat it regardless—this will help you to prevent an emergency.

If you've treated your blood sugar and it's not going up and you continue to have symptoms, call your healthcare professional or go to the emergency room.


Practicing good diabetes self-management is the best way to prevent emergencies from occurring. This includes eating a healthy, modified carbohydrate diet, taking your medicines as prescribed, testing your blood sugar regularly, adopting a regular exercise regimen, keeping regular medical appointments, and avoiding risky behaviors such as extreme alcohol use.

Sometimes, though, you can do everything correctly and still end up with low blood sugar. In this instance, the best way to avoid an emergency is to contact your healthcare professional right away or to go to the emergency room. It's always better to be overly cautious than to avoid or neglect unusual symptoms. 

Lastly, be sure to carry fast-acting carbohydrates (glucose tablets, candy, or juice), extra snacks (whole grain crackers, nuts, low-fat cheese, snack bar, fresh fruit), your blood glucose meter, and your medicines with you.

If you find yourself consistently experiencing hypoglycemia episodes, talk to your doctor about your treatment plan. Small adjustments to your medication can help.

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A Word From Verywell

When you have diabetes, it's important to know what symptoms to watch out for to prevent a medical emergency. Most of the time, emergencies are a result of very high or very low blood sugars. Preventing emergencies by practicing good diabetes self-management is critical, but sometimes these types of events are out of your control. That's why planning ahead and educating yourself and your family members is so important.

If you don't have diabetes but you have symptoms of hypoglycemia, you can temporarily try eating small meals throughout the day to keep the symptoms at bay and your blood sugar at a normal level. However, you need to make it a priority to see your doctor to find out what's causing your low blood sugar.

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Article Sources
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  1. American Diabetes Association. Hypoglycemia (Low Blood sugar)

  2. Joslin Diabetes Center. Avoiding Nighttime Lows

  3. Evans kreider K, Pereira K, Padilla BI. Practical Approaches to Diagnosing, Treating and Preventing Hypoglycemia in Diabetes. Diabetes Ther. 2017;8(6):1427-1435. doi:10.1007/s13300-017-0325-9

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