Hypoglycemia
A fall in blood sugar to below normal levels.
Hypoglycemia, also called low blood sugar or low blood glucose, is a condition defined by a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). It is most commonly caused by medications used to treat diabetes, such as insulin, sulfonylureas, and glinides, and can result in symptoms ranging from headache and shakiness to loss of consciousness, seizures, or death. Whipple's triad is used to properly identify hypoglycemic episodes, requiring the presence of symptoms, a low blood glucose measurement, and resolution of symptoms when blood sugar returns to normal.
Quick Facts
- Field
- Endocrinology, emergency medicine
- Complications
- Loss of consciousness, death, cardiac arrest
- Onset
- Rapid
- Causes
- Medications (insulin, glinides, and sulfonylureas), sepsis, kidney failure, certain tumors, liver disease, malnutrition
- Diagnosis
- Whipple's triad: Symptoms of hypoglycemia, serum blood glucose level <70 mg/dL (3.9 mmol/L), and resolution of symptoms when blood glucose returns to normal
- Treatment
- Eating foods high in simple sugars
- Medication
- Glucose, glucagon
- Frequency
- In type 1 diabetics, mild hypoglycemia occurs twice per week on average, and severe hypoglycemia occurs once per year.
- Deaths
- In type 1 diabetics, 6–10% will die of hypoglycemia.
Facts from the source article.
Lore & Background
Hypoglycemia is most common in people with diabetes treated with insulin, glinides, or sulfonylureas, often due to excessive or poorly timed doses. Risk increases when a person with diabetes has eaten less than usual, recently exercised, or consumed alcohol. Other causes include severe illness, sepsis, kidney failure, liver disease, hormone deficiency, tumors such as insulinomas, inborn errors of metabolism, and several medications. Low blood sugar may also occur in otherwise healthy newborns who have not eaten for a few hours.
Reader's Guide
Hypoglycemia is significant because it is a common and potentially dangerous complication of diabetes treatment, but it can also occur in non-diabetic individuals due to serious illness or other conditions. Proper identification relies on Whipple's triad, as symptoms alone or a single low reading are not specific enough. Treatment involves consuming 10–20 grams of carbohydrate if the person is conscious and able to swallow, or glucagon by injection or insufflation if not. Among people with diabetes, prevention includes learning symptoms, adjusting medications, frequent blood glucose testing, and possibly using continuous glucose monitors with insulin pumps. Recurrent episodes can lead to hypoglycemic unawareness, where symptoms occur at far lower blood glucose levels, increasing the risk of severe hypoglycemia.
Did You Know?
- Symptoms of hypoglycemia typically come on quickly and resolve once blood-glucose levels are restored to normal.
- The blood-glucose level at which symptoms develop may be lower in someone with several prior episodes of hypoglycemia.
- Hypoglycemic unawareness occurs in 20–40% of type 1 diabetics.
- In neonates aged less than 48 hours, the threshold for response to hypoglycemia is 55–65 mg/dL (3.0–3.6 mmol/L).
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