hypoglykaemia

Hypoglykaemia, also spelled hypoglycaemia or hypoglycemia, is a medical condition characterized by abnormally low blood glucose levels. In many guidelines, a plasma glucose level below 3.9 mmol/L (70 mg/dL) is used as a threshold, though symptoms and treatment decisions may vary. Prompt recognition and treatment are essential to prevent serious outcomes.

Common symptoms include shakiness, sweating, rapid heartbeat, hunger, dizziness, and confusion. As glucose levels fall further, coordination problems, difficulty speaking, blurred vision, seizures, or loss of consciousness can occur. In people who regularly experience low glucose, there may be blunted symptoms or delayed recognition, a condition known as hypoglycaemia unawareness.

Causes and risk factors vary. In individuals with diabetes, the most frequent causes are excessive insulin or other glucose-lowering medications, skipped or delayed meals, or unusually high physical activity. Alcohol can worsen hypoglycaemia, especially when meals are skipped. Non-diabetic causes include certain hormonal deficiencies, severe illness, kidney or liver dysfunction, insulin-secreting tumors, and genetic disorders affecting glucose regulation.

Diagnosis relies on measuring blood glucose, ideally during symptoms or after an episode. The Whipple triad—symptoms of hypoglycaemia, low measured glucose, and symptom relief after glucose administration—helps confirm clinically significant events.

Management depends on severity. For mild-to-moderate cases with ability to swallow, quickly absorbed carbohydrates (such as glucose tablets or juice) are recommended, followed by a longer-acting snack. If the person cannot eat or is unconscious, emergency glucagon administration or intravenous glucose in a medical setting is required. Long-term management focuses on adjusting medications, monitoring glucose levels, and education to prevent recurrence.