What’s the difference between hypoglycemia and hyperglycemia?
- Hypoglycemia means low blood sugar and is usually defined as a blood sugar less than 70 mg/dL.
- Hyperglycemia means high blood sugar and is usually defined as blood sugar greater than 125 mg/dL in a person who has not eaten in the last eight hours or more than 180 mg/dL in someone who ate two hours ago.
Diabetes is a common cause of hyperglycemia, but not everyone who has hyperglycemia has diabetes. Hypoglycemia can occur as a side effect of taking insulin for diabetes, but other people may develop hypoglycemia, too.
| Hypoglycemia | Hyperglycemia | |
|---|---|---|
| Definition | Blood sugar less than 70 mg/dL | Fasting blood sugar of more than 125 mg/dL or more than 180 mg/dL two hours after eating |
| Symptoms |
Feeling jittery, tired or dizzy Being hungry, irritable or confused Having a headache Slurring your words |
Extreme thirst Dry mouth Weakness Headache Frequent urination Blurry vision Nausea Confusion Shortness of breath |
| Causes |
Skipping meals or fasting Too much insulin Binge drinking alcohol |
Diabetes |
Mild levels of hypoglycemia can be treated by eating something that contains carbohydrates. If not treated promptly, hypoglycemia can result in seizures or losing consciousness. If a person has lost consciousness because of low blood sugar and therefore cannot eat or drink, then a drug called glucagon can be given.
Hyperglycemia from undiagnosed diabetes can become life-threatening.
If you experience symptoms of either too high or too low blood sugar, seek medical evaluation.
Related questions
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How your body balances glucose
Glucose is a major source of energy for your body. The level of glucose in your blood will go up and down over the course of a day depending on when and what you have eaten and how much activity you are performing. A healthy human body regulates the amount of glucose in the blood within a range of values considered normal.
Your pancreas and liver are both involved in maintaining this balance. Under normal circumstances, when you eat, your pancreas releases the hormone insulin, which helps your body use the energy created from the food you eat. If your body doesn't need the energy right away, it can store it as glycogen in the liver. When your body needs energy, signaled by a decrease in blood sugar, your pancreas releases glucagon. The presence of glucagon tells your liver to release the stored glycogen so that your body can use it for energy.
References
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Hypoglycemia. July 2021. Available at: https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems/low-blood-glucose-hypoglycemia. [Accessed September 20, 2021].
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Managing Diabetes. December 2016. Available at: https://www.niddk.nih.gov/health-information/diabetes/overview/managing-diabetes. [Accessed September 20, 2021].
- Hantzidiamantis PJ, Lappin SL. Physiology, Glucose. StatPearls. 2021 Jan. https://www.ncbi.nlm.nih.gov/books/NBK545201/.
Read next
Does metformin cause hypoglycemia?
Metformin rarely produces hypoglycemia (low blood sugar levels) because it does not change how much insulin is secreted by the pancreas and does not cause high insulin levels. But metformin toxicity or overdosage that causes lactic acidosis has been associated with hypoglycemia. Experts believe the cause may be increased glucose consumption due to anaerobic metabolism, coupled with decreased oral intake of food and carbohydrates, decreased liver glucose production, and decreased glucose absorption. Continue reading
Does Bactrim cause headaches?
Headache is a common side effect with Bactrim (sulfamethoxazole / trimethoprim) and may occur in up to 10% of patients. Low blood sugar, low sodium blood levels and rarely, aseptic meningitis are other side effects of Bactrim that may lead to a headache. Continue reading
How to test for hypoglycemia at home?
You will need a blood glucose meter if you want to test your blood glucose levels for hypoglycemia at home. These are available online or at your local drug store and are safe, easy, and quick to use. There are lots of different types of meters and they can vary in their portability, speed, size, cost, and readability (with larger displays or spoken instructions if you have vision problems). Most devices deliver results in less than 15 seconds and store this information for future use. Continue reading
See also:
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