How to recognize the symptoms of hypoglycemia, or low blood sugar
- Hypoglycemia is the medical term for low blood sugar, which is less than 70 mg/dL.
- Common symptoms of hypoglycemia include feeling irritable, shaky, or anxious.
- To treat hypoglycemia, you should eat 15 grams of carbohydrates and wait 15 minutes to see if your blood sugar levels improve.
- This article was reviewed by Jason R. McKnight, MD, MS, a family-medicine physician and clinical assistant professor at Texas A&M College of Medicine.
Hypoglycemia is the medical term for abnormally low blood sugar, defined as blood sugar less than 70 mg/dL. By comparison, normal blood sugar levels are between 80 mg/dL and 130 mg/dL, while blood sugars higher than that can indicate prediabetes or diabetes.
Hypoglycemia occurs most often in people with diabetes, though it can also happen for people with eating disorders or pancreas conditions like insulinoma.
Here's how you can recognize the signs of low blood sugar, or hypoglycemia, and how to treat yourself effectively.
Signs and symptoms
There are a few common symptoms of low blood sugar. The early signs include:
- Feeling shaky
- Feeling nervous or anxious
- Feeling irritable or angry (this is especially common in children)
- Sweating
- Racing heart
- Confusion
If hypoglycemia isn't treated immediately, severe and dangerous symptoms can develop, including:
- Feeling weak
- Blurred vision
- Tingling
- Coordination problems
- Headache
- Seizures
Each person's body reacts to low blood sugar differently, so the American Diabetes Association (ADA) recommends keeping track of your symptoms to better understand them, especially if you are newly diagnosed with diabetes.
Ultimately, the only way to know for sure that you have hypoglycemia is by checking your blood sugar. If you get a reading lower than 70 mg/dL, even if fasting, you should treat yourself for hypoglycemia, unless you have previously discussed your blood sugar levels with your doctor and they determined that having a lower blood sugar is normal for you.
If you don't have access to blood sugar measurements, but are experiencing symptoms of hypoglycemia, it's best to treat the condition right away rather than wait, according to the ADA.
Causes
For people with diabetes, low blood sugar is often caused by an imbalance between how much medication you're taking — like insulin — and how much food you're eating.
"For example, if you take a lot of medication for the carbohydrates you are going to eat at a meal but then decide you are not that hungry, hypoglycemia will result," says Romy Block, MD, an endocrinologist who practices on the North Side of Chicago.
Insulin medications are designed to increase the level of insulin in your bloodstream. And since insulin's role is to help the body absorb the sugar in your blood, too much insulin can cause blood sugar levels to drop. Because of this, hypoglycemia is sometimes known as insulin shock.
In severe or prolonged cases of insulin shock, the brain may stop functioning normally because it does not have enough glucose (aka blood sugar), leading to seizures or coordination issues.
During the early stages of hypoglycemia, your body also activates the fight-or-flight response, releasing adrenaline and leading to early warning signs like a racing heart rate or feeling nervous. It's important to pay attention to these early symptoms and treat your hypoglycemia, Block says, as these warning signs are your body's way of protecting itself.
Treatment
Hypoglycemia is treated using the 15-15 rule. If you are experiencing symptoms of low blood sugar or have a blood sugar reading of less than 70 mg/dL, you should eat 15 grams of carbohydrates. After 15 minutes, check your blood sugar again, and if it's still below 70 mg/dL, repeat the process.
The following foods contain the necessary 15 grams of carbohydrates, according to Bock and the ADA:
- 4 ounces of juice
- 8 ounces of milk
- 1 tablespoon of sugar or honey
- Glucose tablets, or chewable tablets to raise blood sugar. Follow the instructions on the bottle for dosing.
Children should only have 10 grams of sugar to treat hypoglycemia. If your blood sugar is below 45 mg/dL, Block recommends having 30 to 45 grams of carbohydrates, or seeking medical attention if your symptoms are severe.
In addition, it's important not to eat too much sugar, which can cause your blood sugar to become too high, and lead to the opposite problem — hyperglycemia. It's common for people to want to eat more until they feel better, according to the ADA, but you should only eat 15 grams of carbohydrates, and then wait 15 minutes before eating again.
Consequences
If you experience low blood sugar frequently, you should talk to your doctor about what may be causing it and how to avoid it in the future. It's important to avoid experiencing low blood sugar often, Block says.
This is because when hypoglycemia occurs frequently, you may become less sensitive to those protective signals. "This delays recognition and treatment," Block says. "We call it hypoglycemia unawareness, which is very dangerous."
If someone is experiencing severe signs of hypoglycemia, such as seizures or passing out, call an ambulance, Block says.
People with type 1 diabetes are more susceptible to low blood sugar and should also talk with their doctor about carrying an emergency kit that contains a glucagon pen, which stimulates the liver to release stored glucose and raises blood sugar more quickly than food alone.
Takeaways
People with diabetes, especially those who are on insulin, like type 1 diabetics, should be aware of the risk of hypoglycemia, Block says.
"The best way to prevent hypoglycemia is to have diabetes education and nutrition counseling," she says. "This will help give you the tools to prevent low sugars. It will teach how your individual medications work, when to self adjust, and what to do if you're sick."
A continuous glucose monitor — which measures blood sugar through a sensor under the skin — can also help prevent hypoglycemia by automatically alerting you when blood sugars fall, Block says.