Hypoglycaemia Treatment for Nurses: The 15–15 Rule, Unconscious Patients and Glucagon

Hypoglycaemia (low blood sugar) is one of the most common emergencies in people with diabetes, especially those taking insulin or sulfonylureas such as gliclazide. Most episodes are easy to treat if you act quickly.

Level	Blood glucose	Meaning
Treat	Below 4.0 mmol/L (about 70 mg/dL)	Hypoglycaemia; treat now
Level 2 (significant)	Below 3.0 mmol/L (54 mg/dL)	Clinically important; needs immediate treatment
Level 3 (severe)	Any value	The person needs help from someone else to recover

Symptoms

• Early: sweating, shaking, palpitations, hunger, anxiety, tingling lips
• Later: confusion, slurred speech, unusual behaviour, drowsiness, seizures, loss of consciousness
• Older adults and long-standing diabetes: warning signs may be absent (hypoglycaemia unawareness)

Treatment: conscious and able to swallow (the 15–15 rule)

1. Give 15–20 g of fast-acting carbohydrate, for example 150–200 mL of pure fruit juice or glucose tablets equal to 15–20 g (check the pack).
2. Recheck blood glucose after 10–15 minutes.
3. If still below 4.0 mmol/L, repeat the fast-acting carbohydrate. You can repeat up to three times.
4. If it is still low after three cycles, call for medical help and consider IV glucose or glucagon.
5. Once glucose is above 4.0 mmol/L, give a longer-acting carbohydrate such as two biscuits or a slice of bread, or the next meal if it is due.

Chocolate and other fatty foods raise glucose more slowly, so they are not first choices. Diet drinks contain no sugar.

Conscious but confused or uncooperative

If the patient can still swallow safely, glucose gel squeezed between the gum and cheek may help. If not, treat as below.

Unconscious, fitting or unable to swallow

• Assess airway, breathing and circulation, put the patient in the recovery position and call for urgent help. Give nothing by mouth.
• If IV access is available: IV glucose 10%, 150–200 mL over about 15 minutes (UK JBDS guidance), as prescribed.
• If there is no IV access: glucagon 1 mg IM (0.5 mg for children under 25 kg or under 8 years). Glucagon works less well in people with liver disease, heavy alcohol use or prolonged fasting, or after sulfonylurea overdose.
• Recheck glucose after 10 minutes and repeat treatment if needed.

After the episode

• Do not stop insulin in a person with type 1 diabetes; review the dose instead.
• Find the cause: missed meal, too much insulin, exercise, alcohol, kidney problems or a new drug.
• Monitor glucose closely, as hypoglycaemia caused by sulfonylureas or long-acting insulin can return.
• Document the episode and the treatment, and report it per local policy.
• Teach the patient and family to recognise and treat future episodes.

Related: Normal blood sugar levels chart · DKA nursing management

Sources: Joint British Diabetes Societies for Inpatient Care, The hospital management of hypoglycaemia in adults with diabetes mellitus; American Diabetes Association Standards of Care in Diabetes 2026. Follow your local protocol.