Hypoglycaemia

Last update: November 2023

Hypoglycaemia is an abnormally low concentration of blood glucose. Severe hypoglycaemia can be fatal or lead to irreversible neurological damage.

Blood glucose levels should be measured whenever possible in patients presenting symptoms of hypoglycaemia. If hypoglycaemia is suspected but blood glucose measurement is not available, glucose (or another available sugar) should be given empirically.

Always consider hypoglycaemia in patients presenting impaired consciousness (lethargy, coma) or seizures.

For diagnosis and treatment of hypoglycaemia in neonates, refer to the guide Essential obstetric and newborn care, MSF.

Clinical features

Rapid onset of non-specific signs, mild to severe depending on the degree of the hypoglycaemia: sensation of hunger and fatigue, tremors, tachycardia, pallor, sweats, anxiety, blurred vision, difficulty speaking, confusion, convulsions, lethargy, coma.

Diagnosis

Capillary blood glucose concentration (reagent strip test):

• Non-diabetic patients:
  • Hypoglycaemia: < 3.3 mmol/litre (< 60 mg/dl)
  • Severe hypoglycaemia: < 2.2 mmol/litre (< 40 mg/dl)
• Diabetic patients on home treatment: < 3.9 mmol/litre (< 70 mg/dl) [1] Citation 1. American Diabetes Association. Standards of Care in Diabetes—2023 Abridged for Primary Care Providers. Clinical Diabetes. 2022;41(1):4-31.
  https://doi.org/10.2337/cd23-as01

If blood glucose measurement is not available, diagnosis is confirmed when symptoms resolve after the administration of sugar or glucose.

Symptomatic treatment

• Conscious patients:
  • Children: a teaspoon of powdered sugar in a few ml of water or 50 ml of fruit juice, maternal or therapeutic milk or 10 ml/kg of 10% glucose by oral route or nasogastric tube.
  • Adults: 15 to 20 g of sugar (3 or 4 cubes) or sugar water, fruit juice, soda, etc.

Symptoms improve approximately 15 minutes after taking sugar by oral route.

• Patients with impaired consciousness or prolonged convulsions:
  • Children: 2 ml/kg of 10% glucose by slow IV (2 to 3 minutes) a Citation a. If ready-made 10% glucose solution is not available: remove 100 ml of 5% glucose from a 500 ml bottle or bag, then add 50 ml of 50% glucose to the remaining 400 ml of 5% glucose to obtain 450 ml of 10% glucose solution.  
  • Adults: 1 ml/kg of 50% glucose by slow IV (3 to 5 minutes)

Neurological symptoms improve a few minutes after the injection.

Check blood glucose after 15 minutes. If it is still low, re-administer glucose by IV route or sugar by oral route according to the patient’s clinical condition.

If there is no clinical improvement, differential diagnoses should be considered: e.g. serious infection (severe malaria, meningitis, etc.), epilepsy, unintentional alcohol intoxication or adrenal insufficiency in children.

In all cases, after stabilisation, give a meal or snack rich in complex carbohydrates and monitor the patients for a few hours.

If patient does not return to full alertness after an episode of severe hypoglycaemia, monitor blood glucose levels regularly.

Aetiological treatment

• Other than diabetes:
  • Treat severe acute malnutrition, neonatal sepsis, severe malaria, acute alcohol intoxication, etc.
  • End prolonged fast.
  • Replace drugs inducing hypoglycaemia (e.g. quinine IV, pentamidine, ciprofloxacin, enalapril, beta-blockers, high-dose aspirin, tramadol), or anticipate hypoglycaemia (e.g. administer quinine IV in a glucose infusion).
• In diabetic patients:
  • Avoid missing meals, increase intake of carbohydrates if necessary.
  • Adjust dosage of insulin according to blood glucose levels and physical activity.
  • Adjust dosage of oral antidiabetics, taking into account possible drug interactions.