31 August 2026Chapter 12: Other conditionsPDF page 390Source update: November 2023
Diabetes type 2 in adults
Comprehensive clinical guide to adult type 2 diabetes diagnosis, glycaemic targets, lifestyle care, oral medicines, insulin adjustment, complications, and monitoring.
This guide supports clinical education and care navigation. It does not replace bedside judgement, emergency care, specialist advice, or local treatment protocol.
Seek urgent care
- Confusion, coma, severe dehydration, vomiting, deep illness, or very high blood glucose symptoms.
- Foot ulcer, signs of stroke or heart attack, chest pain, severe weakness, or sudden vision changes.
- Symptoms of hypoglycaemia such as sweating, shaking, confusion, fainting, or seizures in someone using diabetes medicines.
Definition and risks
Type 2 diabetes is a metabolic disorder with persistent hyperglycaemia. It usually occurs in adults and accounts for most diabetes cases worldwide.
The condition may be silent for years. Poorly controlled diabetes increases acute risks such as severe dehydration, hyperosmolar hyperglycaemia, ketoacidosis in selected cases, and hypoglycaemia from treatment, as well as chronic cardiovascular, retinal, kidney, nerve, and foot complications.
Symptoms and signs
- Many adults have few or no symptoms. Symptomatic hyperglycaemia commonly causes polyuria, polydipsia, fatigue, weight change, blurred vision, recurrent infections, or delayed wound healing.
- Rare severe presentations include acute dehydration, impaired consciousness, coma, severe infection, or marked catabolic symptoms.
- Look for diabetes in patients with stroke, myocardial infarction, hypertension, peripheral neuropathy, foot ulcers, absent tendon reflexes, reduced peripheral pulses, recurrent skin infections, or unexplained kidney disease.
Diagnostic thresholds
Diagnosis is made from blood glucose or HbA1c according to available testing. Even in symptomatic patients, confirmatory testing is preferred when feasible and does not delay urgent care.
- Check urine ketones if fasting glucose is >= 15 mmol/litre with hyperglycaemia symptoms, or if fasting or random glucose is >= 18 mmol/litre even without symptoms.
- Refer urgently if hyperosmolar hyperglycaemia, ketoacidosis, severe dehydration, coma, serious infection, or another acute complication is suspected.
| Test | Symptomatic patient | Asymptomatic patient |
|---|---|---|
| Fasting blood glucose after at least 8 hours fasting | One result >= 7 mmol/litre or >= 126 mg/dl | Two fasting results >= 7 mmol/litre or >= 126 mg/dl |
| Random venous blood glucose | One result >= 11 mmol/litre or >= 200 mg/dl | Do not confirm with a second random result; confirm with fasting glucose when possible. |
| Post-load glucose 2 hours after 75 g oral glucose | Venous >= 11 mmol/litre or >= 200 mg/dl, or capillary >= 12.2 mmol/litre or >= 220 mg/dl | Two abnormal post-load results using the same thresholds. |
| HbA1c | One result >= 6.5% | Two results >= 6.5% |
Glycaemic targets and lifestyle care
- Lifestyle and diet advice applies to every patient, whether or not medicines are prescribed.
- Avoid sugared drinks and foods while avoiding extreme carbohydrate restriction. Encourage high-fibre foods, limit animal fats and alcohol, support regular physical activity, stop smoking, and target 5 to 10% weight reduction when BMI is 25 or above.
- Lifestyle measures alone may normalise glucose in some patients but require follow-up to confirm sustained control.
| Measure | Target |
|---|---|
| Fasting blood glucose | At or below 7 mmol/litre, or at or below 126 mg/dl, when safe. |
| HbA1c | Around 7% for many adults; up to 8% may be acceptable for older patients, severe hypoglycaemia history, long-standing poor control, or limited monitoring access. |
| Lower safety limit | Avoid glucose below 4.5 mmol/litre or below 80 mg/dl, and avoid overtreatment aiming for HbA1c below 6.5% when risk outweighs benefit. |
Oral pharmacological treatment
- Use metformin first line when tolerated and not contraindicated. If metformin is contraindicated or not tolerated, use a sulfonylurea according to patient age and hypoglycaemia risk.
- If glycaemic control remains inadequate on metformin, add a sulfonylurea. Titrate sulfonylureas gradually because hypoglycaemia can be severe.
- Review adherence, diet, renal function, adverse effects, infections, steroids, and other hyperglycaemia triggers before escalating treatment.
| Medicine | Practical dosing approach |
|---|---|
| Metformin | Usual total dose 1 to 2 g/day. Start 500 mg once daily with breakfast for week 1, then 500 mg twice daily with meals in week 2. Increase by 500 mg per week as tolerated to a maximum of 2 g/day. |
| Glibenclamide in patients under 60 years | Usual dose 5 mg twice daily. Start 2.5 mg once daily with breakfast for week 1, then 5 mg once daily in week 2. Increase by 2.5 mg weekly according to fasting glucose to a maximum of 15 mg/day. |
| Gliclazide immediate release in patients over 60 years | Usual dose 40 to 80 mg twice daily. Start 40 mg once daily with breakfast for 2 weeks, then increase by 40 mg every 2 weeks according to fasting glucose to a maximum of 240 mg/day. |
Insulin when oral therapy is insufficient
If control is not achieved with metformin plus sulfonylurea, continue metformin and replace the sulfonylurea with intermediate-acting insulin given subcutaneously. Start around 0.2 IU/kg at bedtime and adjust from morning fasting glucose.
- Once glucose stabilises, test fasting glucose once weekly if possible and again after each consultation or dose change.
- Doses of 1 IU/kg/day or more may be required. If more than 0.5 IU/kg/day is needed, divide into two daily injections according to local insulin protocol.
- Teach injection technique, timing, injection-site rotation, storage, recognition and treatment of hypoglycaemia, and when to seek urgent care.
| Morning blood glucose | Action |
|---|---|
| Under 4 mmol/litre or under 70 mg/dl | Treat hypoglycaemia, reduce the daily insulin dose by 2 to 4 units, maintain the new dose for 4 days, then recheck. |
| 4 to under 7.2 mmol/litre or 70 to under 130 mg/dl | Maintain the same dose. |
| 7.2 to under 11 mmol/litre or 130 to under 200 mg/dl | Increase daily insulin dose by 2 units, keep for 4 days, then recheck and continue stepwise adjustment until target is reached. |
| 11 mmol/litre or above, or 200 mg/dl or above | Increase daily insulin dose by 4 units, recheck after 4 days, and check urine ketones if criteria are met. |
Surveillance, complications, and education
- For patients on oral hypoglycaemic medicines, check blood glucose monthly at the beginning, then at routine monitoring visits. For patients on insulin, check fasting glucose during dose adjustment and weekly after stabilisation when feasible.
- Check HbA1c every 3 months when available until control is stable, then every 6 months.
- At routine visits, check blood pressure, weight, adherence, adverse effects, hypoglycaemia episodes, infections, and feet. Blood pressure should generally remain below 140/80 mmHg when feasible.
- During annual or periodic review, assess cardiovascular risk, neuropathy, renal function with creatinine and proteinuria dipstick when available, retinopathy or visual symptoms, teeth and gums, foot deformity, ulcers, pulses, footwear, smoking, and alcohol use.
- Manage complications actively: hypoglycaemia, hyperglycaemic emergencies, foot lesions, infection, kidney disease, cardiovascular disease, stroke risk, neuropathic pain, and visual impairment.
- Educate patients on diet, activity, medication adherence, hyperglycaemia and hypoglycaemia signs, self-monitoring where a glucometer is available, foot self-examination for neuropathy or peripheral arterial disease, and not stopping medicines without review.
- Handover should include diagnostic tests, HbA1c or fasting glucose trend, current medicines and doses, hypoglycaemia history, ketones if checked, renal function, foot findings, blood pressure, comorbidities, education given, and next monitoring date.
Medicines in this guide
Metformin oralFirst-line pharmacological treatment when tolerated and not contraindicated.Glibenclamide oralSulfonylurea option, generally for adults under 60 years in this pathway.Gliclazide oralSulfonylurea option preferred over glibenclamide for many older adults in this pathway.Insulin injectableUsed when oral therapy is insufficient or acute circumstances require insulin.Insulin short-acting injectableRelevant for acute hyperglycaemic emergencies and hospital protocols.
Source
MSF Clinical guidelines - Diagnosis and treatment manual (December 2024)
This page is a paraphrased clinician-oriented guide derived from the source topic on PDF page 390. Medicine-specific details should be checked against local protocol and the linked drug-information pages.