Table of Contents
Diabetes mellitus is a chronic condition characterised by high blood glucose (sugar) due to defects in insulin production, insulin action, or both. Early recognition of symptoms and timely, evidence-based treatment reduce the risk of acute emergencies and long-term complications. This article summarises the common and warning symptoms, explains how diabetes is diagnosed, outlines treatment strategies for type 1 and type 2 diabetes, and explains emergency signs and when to seek immediate medical attention.
Why symptoms appear: a brief physiology
When insulin is insufficient or ineffective, glucose builds up in the bloodstream instead of entering cells that need it for energy. The body responds in several ways — trying to remove excess glucose via urine, signalling hunger as cells starve, and triggering fluid shifts that produce thirst and tiredness. Over time, uncontrolled high glucose damages blood vessels and nerves, causing complications in the eyes, kidneys, heart and feet.
Common symptoms of diabetes
Symptoms can be subtle (especially in type 2) or develop rapidly (often in type 1). Key signs to watch for include:
- Frequent urination (polyuria) — the body removes excess glucose via urine.
- Excessive thirst (polydipsia) — loss of fluid triggers intense thirst.
- Unexplained weight loss — more common in type 1 when insulin is very low.
- Persistent hunger (polyphagia) — cells deprived of glucose prompt increased appetite.
- Extreme fatigue — lack of cellular energy.
- Blurred vision — fluctuating eye lens fluid from high glucose.
- Poor wound healing and frequent infections — caused by impaired immunity and circulation.
- Numbness, tingling or pain in feet/hands (neuropathy) — long-term nerve damage from chronic high glucose.
Differences in symptom patterns: Type 1 vs Type 2
Type 1 diabetes often presents suddenly with pronounced symptoms (weight loss, vomiting, dehydration) and can progress to diabetic ketoacidosis if untreated. Type 2 diabetes typically develops gradually; many people have mild or no symptoms for years and are diagnosed during routine testing or when complications appear.
| Feature | Type 1 | Type 2 |
|---|---|---|
| Onset | Rapid (days–weeks) | Gradual (months–years) |
| Typical age | Children, adolescents, young adults | Adults (increasingly younger ages) |
| Weight change | Often loss | Often stable or gain |
| Core treatment | Insulin | Lifestyle ± oral meds ± insulin |
How diabetes is diagnosed
Diagnosis relies on blood glucose measurements: fasting plasma glucose, random plasma glucose with symptoms, oral glucose tolerance test (OGTT), or glycated haemoglobin (HbA1c). Your clinician will choose the appropriate test and interpret results in the clinical context.
- Initial assessment: symptom review and risk factors (family history, BMI, age).
- Blood testing: fasting glucose, HbA1c or OGTT as indicated.
- Confirm diagnosis: repeat testing or use standard thresholds per guidelines.
Treatment principles — lifestyle, monitoring, and medication
Management aims to normalise blood glucose, reduce cardiovascular risk, and prevent complications. Core elements include:
- Medical nutrition therapy (MNT): structured meal planning focusing on balanced carbohydrates, healthy fats and adequate protein.
- Regular physical activity: improves insulin sensitivity and cardiovascular health.
- Self-monitoring: home glucose testing or continuous glucose monitoring (CGM) for some patients.
- Medications: oral agents (metformin, SGLT2 inhibitors, DPP-4 inhibitors, sulfonylureas, etc.) for many people with type 2; insulin therapy is essential for type 1 and sometimes needed in type 2.
- Cardiovascular risk management: blood pressure and lipid control, smoking cessation and aspirin when indicated.
Acute complications and emergencies
Two life-threatening emergencies related to high blood sugar are diabetic ketoacidosis (DKA) (more common in type 1) and hyperosmolar hyperglycaemic state (HHS) (more common in type 2). Both require urgent medical treatment: intravenous fluids, insulin, electrolyte monitoring/replacement, and treatment of triggering causes such as infection. Early recognition and hospital management save lives.
Low blood sugar (hypoglycaemia): recognition and first aid
Hypoglycaemia occurs when blood glucose falls too low (often :4.0 mmol/L, though individual thresholds vary). Symptoms include sweating, trembling, hunger, dizziness, impaired concentration, slurred speech, and in severe cases seizures or loss of consciousness. Immediate treatment is crucial: give 15–20 grams of fast-acting carbohydrate (juice, glucose tablets), recheck glucose after 15 minutes, and repeat if still low. If the person cannot swallow or is unconscious, call emergency services — trained responders may use glucagon injection or intravenous glucose.
Recognising DKA
Look for polyuria, polydipsia, nausea/vomiting, abdominal pain, deep rapid breathing (Kussmaul) and a fruity breath smell. DKA often follows insulin omission, infection or other stressors.
Quick steps for a hypo
Give 15–20 g fast carbs — e.g., 150–200 ml fruit juice, 3–4 glucose tablets, or 1–2 tablespoons of sugar/honey. Wait 15 minutes and recheck. Follow with a snack or meal that contains complex carbohydrates to prevent recurrence.
When to call for help
Call emergency services for persistent vomiting, severe dehydration, altered consciousness, seizures, or if a hypo cannot be corrected at home.
Prevention of hypoglycaemia
Adjust insulin or sulfonylurea dosing around meals and exercise; carry fast-acting carbs; wear medical identification if dependent on insulin.
Long-term complication prevention
Good glycaemic control reduces the risk of microvascular complications (retinopathy, nephropathy, neuropathy). Regular screening is essential: eye exams, urine tests for albumin, foot checks, and cardiovascular risk assessment. Treat comorbid conditions (hypertension, dyslipidaemia) aggressively to lower overall risk.
| Area | Action | Frequency |
|---|---|---|
| Retinopathy screening | Dilated eye exam | Annually or per specialist advice |
| Kidney function | Urine albumin and serum creatinine | At least annually |
| Foot health | Foot examination and education | Every visit / annually |
Practical self-care tips
- Follow your personalised meal and medication plan.
- Monitor your blood glucose as advised and keep records to share with your care team.
- Stay active — aim for regular moderate exercise, adjusted safely for medications.
- Attend regular follow-ups and screening appointments.
- Learn the signs of high and low blood sugar and keep a hypo kit on hand (fast-acting carbs and glucagon if prescribed).
What are the earliest signs of diabetes?
Early signs can include increased thirst, frequent urination, fatigue, blurred vision, and slow-healing wounds. Many people with type 2 have mild or no symptoms at first.
Can diabetes be cured?
Type 1 diabetes currently has no cure and requires lifelong insulin. Some people with type 2 diabetes achieve remission through substantial and sustained weight loss and lifestyle changes, but ongoing monitoring remains essential.
When should I go to the emergency room?
Go to the ER for severe symptoms such as difficulty breathing, persistent vomiting, confusion, seizures, coma, or very high blood glucose with dehydration—possible signs of DKA or HHS.
How often should I monitor my blood sugar?
Monitoring frequency depends on your type of diabetes and treatment. Insulin users often test multiple times daily; others may test less frequently or use HbA1c and intermittent monitoring—follow your clinician’s plan.
WHO — Diabetes overview & guidance“Early recognition and partnership with your healthcare team are the cornerstones of living well with diabetes.”
— Endocrinology Specialist
