⚡ Men's Health

Hypoglycaemia — Low Blood Sugar Emergencies

Recognising, treating, and preventing dangerously low blood sugar

Hypoglycaemia — low blood sugar (glucose < 3.9 mmol/L or 70 mg/dL) — is the most common acute complication of diabetes treatment and a major barrier to achieving good blood sugar control. Severe hypoglycaemia (requiring assistance from another person) causes confusion, loss of consciousness, seizures, cardiac arrhythmias, and death. In Nigeria, hypoglycaemia is responsible for significant diabetes-related deaths — particularly in patients on sulphonylureas (glibenclamide) and insulin without adequate self-monitoring. Fear of hypoglycaemia also causes many patients to deliberately keep their blood sugar high, leading to long-term complications.

Signs and Symptoms

✓ Mild (glucose 3.0–3.9 mmol/L): shakiness, sweating, palpitations, hunger, tingling around mouth, anxiety

✓ Moderate (glucose 2.0–3.0 mmol/L): difficulty concentrating, confusion, blurred vision, headache, irritability, slurred speech

✓ Severe (glucose < 2.0 mmol/L): inability to self-treat, seizures, loss of consciousness, coma

✓ Hypoglycaemia unawareness: some long-term diabetics lose the warning symptoms — first sign may be confusion or collapse. Extremely dangerous

✓ Nocturnal hypoglycaemia: waking sweating, nightmares, morning headache, inexplicably high morning glucose (Somogyi effect)

Risk Factors

Sulphonylureas (glibenclamide, glimepiride, gliclazide): stimulate insulin secretion regardless of blood glucose. Particularly dangerous in elderly and those with kidney disease
Insulin therapy: any insulin can cause hypoglycaemia. Mismatch between dose, food intake, and exercise
Renal impairment: reduces drug and insulin clearance — doses accumulate
Irregular or insufficient food intake: skipping meals, reduced appetite during illness
Increased exercise without dose adjustment
Alcohol: impairs hepatic glucose release (gluconeogenesis) — hypoglycaemia hours after drinking
Elderly patients: reduced glucagon counter-regulatory response, hypoglycaemia unawareness

When to Seek Help

Blood glucose < 3.9 mmol/L with symptoms — treat immediatelyFollow the 15-15 rule: 15g fast-acting sugar, wait 15 minutes, recheck. Repeat if still low

Unconscious or fitting diabeticEmergency. Give IM glucagon (if available) or IV dextrose (50% = 25mL, or 10% = 125mL). Call for emergency help. Do NOT give anything by mouth to an unconscious person

Recurrent hypoglycaemia (more than twice per week)Treatment adjustment needed — medication review, glucose monitoring optimisation, dietary counselling

Hypoglycaemia unawareness suspectedSpecialist review — insulin regimen change, use of continuous glucose monitoring

Any hypoglycaemia from sulphonylurea overdose or renal failureThese last much longer than insulin-related hypoglycaemia — prolonged IV dextrose infusion and hospital observation for 24+ hours needed

Tests & Diagnosis

🧪 Blood glucose (finger-prick glucometer)

The essential test. Every diabetic on insulin or sulphonylureas should have access to a glucometer

🧪 HbA1c

HbA1c < 6.5% in a diabetic on hypoglycaemia-prone medication — target too tight for this patient, adjust upwards

🧪 Renal function

Reduced eGFR increases sulphonylurea and insulin accumulation — dose reduction or drug switch required

🧪 Liver function

Hepatic disease impairs gluconeogenesis — increased hypoglycaemia risk

🧪 Insulin and C-peptide

If hypoglycaemia occurs in someone not on diabetes medication — to exclude insulinoma or factitious hypoglycaemia

Treatment Options

Conscious patient — mild to moderate hypoglycaemia

15g fast-acting carbohydrate: 150–200mL of fruit juice or regular soft drink (not diet), 3–4 teaspoons of sugar, 4 glucose tablets, or 2–3 teaspoons of honey. Wait 15 minutes. Recheck glucose. If still < 3.9 mmol/L, repeat. Once > 4 mmol/L, eat a slow-release snack (bread, plantain, beans) to prevent recurrence

Unconscious or fitting patient

IV dextrose: 50mL of 50% dextrose or 150mL of 10% dextrose IV. Or IM glucagon 1mg if available (not widely available in Nigeria). NEVER give oral food/drink to unconscious person — aspiration risk

Prevention: medication review

Is glibenclamide (notorious for severe prolonged hypoglycaemia) the safest choice? Gliclazide MR has lower hypoglycaemia risk. Metformin alone does not cause hypoglycaemia. SGLT-2 inhibitors and GLP-1 analogues have very low hypoglycaemia risk

Carbohydrate consistency

Educate patients on consistent carbohydrate intake with each meal to match insulin or sulphonylurea action. Skipping meals is the most preventable cause

Hypoglycaemia unawareness management

Strict avoidance of hypoglycaemia for 2–3 weeks partially restores awareness. Relax blood glucose targets. Consider continuous glucose monitoring (CGM) — increasingly available in Nigeria

Frequently Asked Questions

What is the 15-15 rule?

When blood glucose is below 3.9 mmol/L (70 mg/dL) with symptoms: take 15 grams of fast-acting carbohydrate (15g = 3 teaspoons of sugar, or 150mL fruit juice, or 4 glucose tablets), wait 15 minutes, recheck blood glucose. If still below 3.9, repeat. Once above 4.0 mmol/L, eat a small slow-release snack to prevent recurrence. This simple rule prevents most hypoglycaemia episodes from escalating.

Can sugar cause hypoglycaemia?

No — in people without diabetes or non-diabetes medications, even large amounts of sugar don't cause hypoglycaemia. What causes hypoglycaemia is taking too much insulin or sulphonylurea for the amount of food eaten, or not eating enough after taking medication. The treatment for hypoglycaemia is sugar — sugar doesn't cause it in diabetics either, unless they've severely over-treated.

How do I know if my loved one is having a hypo?

Common signs: sudden unusual behaviour, confusion, shakiness, sweating, pale appearance, aggression or unusual personality change, seizure, or unconsciousness in a known diabetic. Always check blood glucose first in any unusual behaviour in a diabetic. Give sugar to a conscious person who can swallow safely.

Glibenclamide (glibenclamide) is very cheap — can I still use it?

Glibenclamide is the cheapest sulphonylurea and remains widely used in Nigeria. However, it carries the highest hypoglycaemia risk among sulphonylureas — particularly dangerous in elderly patients and those with kidney disease. If hypoglycaemia has occurred or the patient is elderly or has CKD, switching to gliclazide MR (slightly more expensive but much safer) or metformin-based regimens is strongly recommended.