What Is Hypoglycemia?

Hypoglycemia means your blood sugar is too low. Hypoglycemia is most often related to diabetes treatment, and symptoms of low blood sugar need immediate attention.

Hypoglycemia is the medical term indicating your blood sugar (also called glucose) level has dropped below normal. Although several conditions may cause hypoglycemia, it’s most often associated with diabetes treatment.

Hypoglycemia is usually indicated by a blood glucose level that’s less than 70 mg/dL. However, the American Diabetes Association (ADA) notes that figure can vary somewhat. So, if you have diabetes, talk to your doctor about your own blood sugar targets and what level is too low for you.

Hypoglycemia can cause severe and even life-threatening symptoms if not treated promptly. That’s why it’s important for people with diabetes to recognize the symptoms of low blood sugar, test their blood sugar regularly, and know how to take action to bring low blood glucose back into a healthy target range.

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What causes hypoglycemia if you have diabetes?

Although insulin is extremely important in treating type 1 diabetes and, sometimes, is needed to control type 2 diabetes, it often plays a role in causing hypoglycemia.

Type 1 diabetes is an autoimmune disease marked by the pancreas producing no, or very little, insulin — the hormone your body needs to move blood sugar into cells for energy. The result is an accumulation of blood sugar to dangerous levels unless there is daily treatment with adequate insulin.

In type 2 diabetes, your pancreas produces insulin, but your body doesn’t use it effectively, resulting in blood sugar levels that are too high. The condition is primarily one of lifestyle (being overweight and sedentary) and can often be controlled with regular exercise, losing excess pounds and eating a healthy diet. However, when blood sugar levels remain elevated too often, oral medications, including insulin, may be needed.

Insulin lowers blood sugar levels, but, when you take too much insulin, it can cause hypoglycemia — and type 1 diabetics are at greater risk of serious low blood sugar reactions (also called insulin reaction or insulin shock) than people with type 2 diabetes. That’s because, unlike people with type 2 diabetes, those with type 1 must take insulin daily to live and need to adjust their injections carefully depending on diet, stress, and other factors.

In addition to happening if you accidentally inject excess insulin, or the wrong type by mistake, hypoglycemia can result from injecting insulin directly into your muscle instead of just under the skin (a subdermal injection).

What’s more, although regular physical activity is important for health — whether you have diabetes or not — intense exercise can result in low blood sugar episodes in some people with type 1 diabetes, the ADA notes.

Overall, the average person with type 1 diabetes likely experiences up to two episodes of mild low blood sugar with symptoms every week, according to the ADA. Although far more likely to occur in people with type 1 diabetes, low blood sugar episodes can occur in those with type 2 diabetes who are taking insulin or medications prescribed for their condition that may impact blood glucose.

What and how people with diabetes eat can cause low blood sugar, too. For example, if a person regularly takes a certain amount of insulin and they eat fewer carbohydrates than usual without reducing the amount of insulin they take, blood sugar levels may drop. Drinking carb-containing liquids can be problematic because your body absorbs them much faster than solid food. That can make timing an insulin dose and adjusting the amount to keep blood sugar from spiking tricky, especially for someone with type 1 diabetes.

Recognizing hypoglycemia symptoms

Although symptoms of hypoglycemia can vary between people, low blood glucose triggers the release of adrenaline, which can cause symptoms associated with the “fight-or-flight” response — like a racing heart, tingling, anxiety, and sweating.

Other common mild-to-moderate symptoms of hypoglycemia include:

• Hunger
• Headaches
• Blurred vision
• Dizziness
• Unusual sleepiness or fatigue
• Changes in behavior
• Difficulty with concentration
• Lack of coordination
• Feeling confused or disoriented
• Pale skin
  

If severe, hypoglycemia can be dangerous, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) emphasizes. Severe hypoglycemia symptoms include being unable to eat or drink, experiencing seizures or convulsions, and becoming unconscious.

Severe low blood sugar may even make you unable to treat yourself with insulin and require help from another person. This type of extreme hypoglycemia is primarily seen in people with type 1 diabetes.

To avoid a severe low blood sugar crisis, it’s crucial to understand blood sugar levels can plummet quickly. If you have diabetes, always keep a fast-acting carbohydrate with you, such as juice or glucose tablets, so that you can treat a falling blood sugar level before it dips dangerously low.

It’s also important to discuss with your doctor how often to test your blood sugar level with a blood glucose meter. Knowing your target blood sugar levels can help you decide how much insulin and other medicine to take, what food to eat, and how physically active you should be.

Non-diabetes causes of hypoglycemia

Although diabetes is the condition most often associated with low blood sugar there are some other causes. Surprisingly, prolonged fasting rarely causes hypoglycemia in healthy people. However, drinking alcohol heavily without eating can cause blood sugar to fall.

Advanced liver disease and liver cancer can disrupt blood sugar control and may cause hypoglycemia, according to the Merck Manual. Some rare tumors of the pancreas can also result in hypoglycemia and so can conditions which lower hormone levels, like Addison’s disease. Chronic kidney disease and heart failure may also be associated with episodes of abnormally low blood sugar, too.

After undergoing bariatric surgery, such as gastric bypass surgery for weight loss, some people experience excessive insulin production that can cause hypoglycemia.

Eating a meal loaded with a very large amount of carbohydrates can trigger a temporary condition called reactive hypoglycemia — which means your body produces more insulin than it needs in reaction to the carbs and blood sugar drops, causing symptoms. However, this reaction is rare.

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