Symptoms of Hypoglycemia (Low Blood Sugar)

If you have diabetes, you may very well be familiar with the types of symptoms a blood glucose reading 70 milligrams per deciliter (mg/dL) or below causes. The most common symptoms of hypoglycemia include shakiness, a fast heartbeat, anxiety, and hunger.

If your blood sugar gets dangerously low, you may have symptoms like confusion, vision difficulties, behavioral changes, seizures, or even loss of consciousness.

Hypoglycemia can occur in those without diabetes as well. Fortunately, eating or drinking some simple carbohydrates can usually provide a quick fix—but to do that you need to be able to identify the symptoms of hypoglycemia.

common hypoglycemia symptoms

Verywell / Laura Porter

Hypoglycemia Symptoms

The symptoms of hypoglycemia tend to follow a pattern that you'll probably very quickly learn to recognize if you have diabetes.

Frequent Symptoms

Common symptoms include:

  • Shakiness
  • Hunger
  • Fast heartbeat
  • Anxiety or panic
  • Tingling feeling around your mouth
  • Sweating
  • Headache
  • Tiredness
  • Inability to concentrate
  • Dilated pupils
  • Irritability
  • Restlessness
  • Nausea
  • Dizziness
  • Weakness
  • Loss of muscle control

Severe Symptoms

When your blood sugar becomes dangerously low—less than 54 mg/dL, as defined by the American Diabetes Association (ADA), which regards this parameter as severe or "level 2" hypoglycemia— you may have any of these symptoms as well:

Nocturnal Symptoms

During the night, you may have hypoglycemic episodes and not be aware of them. This is especially common with type 1 diabetes and a bit less common with type 2 diabetes.

Your body produces two hormones, glucagon and epinephrine, that help keep your blood sugar at normal levels. During sleep, glucagon production decreases. Added to this, type 1 diabetes tends to disrupt glucagon production and glucagon decreases with every episode as well.

Symptoms of nocturnal symptoms include:

  • Night sweats
  • Nightmares
  • Talking or shouting in your sleep
  • Restlessness
  • Headache
  • Not feeling well-rested when you wake up
  • A glucose level that's higher than normal in the morning

To help prevent nocturnal hypoglycemic episodes, try eating a bedtime snack that's high in complex carbohydrates such as granola, oatmeal, or dried fruit. Keep your eating plan, exercise routine, and medication consistent in the afternoon and evening as well.

Also, be careful not to overdose on your insulin in the evening, which can lead to hypoglycemia.

Get Medical Attention

If you notice symptoms of nocturnal hypoglycemia, talk to your healthcare provider. Untreated, it can lead to life-threatening hypoglycemia, which can result in severe symptoms.

Hypoglycemia Unawareness

When you have diabetes and you have repeated episodes of hypoglycemia, your brain can become less able to recognize that you're hypoglycemic because your body stops showing symptoms. This is known as hypoglycemic unawareness and it often happens at night while you're sleeping.

It's more common in type 1 diabetes than in type 2. Your blood sugar levels can become dangerously low if this continues, leading to a coma or even death.

If you have chronic episodes of hypoglycemia, be sure to talk to your healthcare provider right away so you can get it under control.

Hypoglycemia Causes

Hypoglycemia has numerous causes, which are different depending on whether you have type 1 diabetes, type 2 diabetes, or don't have diabetes.

Type 1 Diabetes

Hypoglycemia is common in type 1 diabetes. It usually happens when you take more insulin than your body needs to process your food, but other things can cause it, too, including:

  • Not timing your insulin dose correctly around meals
  • Not monitoring your blood sugar closely when exercising or drinking alcohol
  • Hot, humid weather
  • Changes in your schedule, such as when traveling
  • Being at a high altitude
  • Puberty
  • Menstrual periods

Because you can't control some of those factors, it's especially important to pay attention to the ones you can control.

Type 2 Diabtes

Hypoglycemia is less common in type 2 diabetes than in type 1. It's often caused by:

  • Medications: Taking too much medication, including insulin
  • Food: Eating too few carbohydrates compared to your insulin
  • Drinking carbohydrates: Your body absorbs carbs from liquids faster than from solids, so your insulin timing may prove difficult
  • Physical activity: Exercise lowers your insulin needs

Newer insulins and diabetes medications are less likely to result in hypoglycemia.

No Diabetes

Non-diabetic hypoglycemia can be caused by many things, including:

  • Some medications (beta-blockers, some antibiotics, heart arrhythmia medications)
  • Alcohol consumptio
  • Underlying kidney, liver, or metabolic illness
  • Undereating
  • Hormonal deficiencies
  • A rare pancreatic tumor (insulinoma) causing insulin overproduction
  • Recent bariatric surgery
  • Insulin autoimmune syndrome
  • Reactive hypoglycemia

Complications

If hypoglycemia remains untreated, it can lead to any of the severe symptoms mentioned above, such as seizures, unconsciousness, and, eventually, death. This is why it's critical to treat low blood sugar immediately, no matter the cause.

Hypoglycemia can also be a contributing factor in:

  • Falls
  • Motor vehicle accidents
  • Other injury-causing accidents

Because hypoglycemia isn't a disease but an indication of another problem, it's extremely important that you and your healthcare provider figure out the cause, especially if you don't have diabetes or have diabetes with repeated hypoglycemia episodes.

When to See a Healthcare Provider

When to get medical help for hypoglycemia depends on whether you have diabetes.

If You Don't Have Diabetes

If you don't have diabetes and you have symptoms of hypoglycemia, you should see your healthcare provider right away, even if you're able to get your symptoms to subside.

You can try to treat your hypoglycemia by eating/drinking one of the following:

  • 4 ounces of juice or non-diet soda
  • A serving of jellybeans (check the package for serving size)
  • A banana
  • 8 ounces of milk
  • 1 tablespoon of honey or corn syrup
  • 2 tablespoons of raisins

Being hypoglycemic means something else is going on and you need to find out what that is. Then, you can get treatment before your hypoglycemia becomes life-threatening.

If you still have symptoms after treating your low blood sugar with the above measures, go to the emergency room immediately.

If You Have Diabetes

If you have diabetes, you'll most likely deal with hypoglycemia on occasion. If your blood sugar is below 70 mg/dl, try one of the remedies detailed above or take glucose tablets as directed by the package.

As long as your blood sugar goes back to normal, you can resume your regular activities. However, if you've treated your hypoglycemia and your blood sugar remains low and/or you still have symptoms, contact your healthcare provider as soon as possible.

You should also visit with your healthcare provider right away if you have symptoms of nocturnal hypoglycemia and/or recurring episodes of hypoglycemia since these can turn into serious, potentially life-threatening, problems if they're not treated.

Get emergency help for severe symptoms such as:

  • Behavioral changes
  • Confusion
  • Visual changes
  • Slurred speech
  • Seizures
  • Unconsciousness

Frequently Asked Questions

  • What causes hypoglycemia unawareness?

    It’s unclear, but the longer you live with diabetes, the more likely you are to become unaware when you have symptoms of hypoglycemia.

    It’s possible that diabetes, especially type 1 diabetes, causes changes in the way the brain uses glucose over time, which impairs the brain’s ability to respond to signs of hypoglycemia. More research is needed, though, to understand the condition.

  • What does a hypoglycemic attack feel like?

    You may feel shaky and weak at first. Other common signs of a hypoglycemic attack include:

    • Sweating
    • Headache
    • Vision changes
    • Sudden mood changes and increased irritability 

    If symptoms aren’t treated, it can lead to confusion, seizures, or a loss of consciousness.

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13 Sources
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.
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