1. What is Diabetes Mellitus?
Diabetes Mellitus is a chronic metabolic disorder characterized by high blood sugar levels (hyperglycemia) due to insufficient insulin production or improper insulin use. Glucose is the body’s primary energy source, and insulin, a hormone from the pancreas, regulates glucose levels.
Types of Diabetes Mellitus
- Type 1 Diabetes – The body produces little or no insulin due to autoimmune destruction of pancreatic beta cells. Commonly diagnosed in children and young adults.
- Type 2 Diabetes – The body becomes resistant to insulin or does not produce enough. The most common type, linked to lifestyle and genetics.
- Gestational Diabetes – Develops during pregnancy and increases the risk of Type 2 diabetes later in life.
- Other Rare Types – MODY (Maturity Onset Diabetes of the Young), LADA (Latent Autoimmune Diabetes in Adults), and secondary diabetes from pancreatic diseases or medications (e.g., steroids).
2. Symptoms of Diabetes Mellitus
Common Symptoms of All Types of Diabetes
- Increased urination (Polyuria) – Due to excess glucose pulling water into urine.
- Excessive thirst (Polydipsia) – Resulting from dehydration.
- Unexplained weight loss – More common in Type 1 due to fat and muscle breakdown.
- Increased hunger (Polyphagia) – Cells lack glucose for energy.
- Fatigue and weakness – Poor glucose utilization.
- Blurred vision – Due to fluid shifts affecting the eye lens.
- Slow-healing wounds – High glucose levels impair healing and increase infection risk.
- Numbness or tingling in hands and feet – Due to nerve damage (diabetic neuropathy).
3. Diagnostic Tests for Diabetes Mellitus
Procedures for the Tests
- Fasting Blood Sugar (FBS): The patient must fast for at least 8 hours before a blood sample is drawn.
- Random Blood Sugar (RBS): A blood sample is taken at any time, regardless of when the patient last ate.
- Oral Glucose Tolerance Test (OGTT): The patient fasts overnight, drinks a glucose solution, and blood samples are taken at intervals (usually 2 hours later) to measure glucose response.
- HbA1c Test: Measures the average blood sugar level over the past 3 months using a standard blood sample.
Diabetes is diagnosed using the following tests, with values in mmol/L and mg/dL:
| Test | Normal | Prediabetes | Diabetes |
| Fasting Blood Sugar (FBS) | <5.6 mmol/L (<100 mg/dL) | 5.6–6.9 mmol/L (100–125 mg/dL) | ≥7.0 mmol/L (≥126 mg/dL) |
| Random Blood Sugar (RBS) | <7.8 mmol/L (<140 mg/dL) | 7.8–11.0 mmol/L (140–199 mg/dL) | ≥11.1 mmol/L (≥200 mg/dL) |
| Oral Glucose Tolerance Test (OGTT, 2 hours after 75g glucose) | <7.8 mmol/L (<140 mg/dL) | 7.8–11.0 mmol/L (140–199 mg/dL) | ≥11.1 mmol/L (≥200 mg/dL) |
| HbA1c (3-month average blood sugar levels) | <5.7% | 5.7–6.4% | ≥6.5% |
4. Risk Factors for Developing Diabetes Mellitus
Risk Factors for Type 1 Diabetes
- Family history (genetic predisposition)
- Autoimmune diseases (thyroid disease, celiac disease)
- Viral infections (Coxsackie virus, rubella, Epstein-Barr virus)
- Environmental triggers (low vitamin D, early exposure to cow’s milk)
Risk Factors for Type 2 Diabetes
- Overweight or obesity (BMI ≥25)
- Sedentary lifestyle
- Unhealthy diet (high sugar, processed foods)
- High blood pressure and cholesterol
- Family history of Type 2 diabetes
- Age >45 years
- Polycystic Ovary Syndrome (PCOS)
- Gestational diabetes history
Risk Factors for Gestational Diabetes
- Previous gestational diabetes
- Obesity before pregnancy
- Family history of diabetes
- Age >25 years
- High blood pressure during pregnancy
5. Complications of Diabetes Mellitus and Their Presentation
Short-Term Complications
- Diabetic Ketoacidosis (DKA): Life-threatening condition caused by a severe lack of insulin. Symptoms include nausea, vomiting, fruity breath, deep rapid breathing, dehydration, confusion, and abdominal pain. Requires emergency treatment with insulin and IV fluids.
- Hyperosmolar Hyperglycemic State (HHS): More common in Type 2 diabetes, characterized by extremely high blood sugar levels leading to severe dehydration, confusion, and potential coma. Requires IV fluid replacement and insulin therapy.
- Hypoglycemia (Low Blood Sugar): Caused by too much insulin or skipping meals. Symptoms include sweating, shakiness, dizziness, confusion, fast heartbeat, and, in severe cases, loss of consciousness or seizures.
Long-Term Complications
- Diabetic Retinopathy: Damage to the blood vessels in the retina, leading to vision problems, blurry vision, floaters, and, if untreated, blindness.
- Diabetic Neuropathy: Nerve damage causing tingling, numbness, burning pain, or weakness, usually in the legs and feet. Severe cases can lead to loss of sensation and ulcer formation.
- Diabetic Nephropathy: Kidney damage due to prolonged high blood sugar, leading to protein leakage in urine, swelling, high blood pressure, and eventual kidney failure requiring dialysis or transplantation.
- Cardiovascular Disease: Increased risk of heart disease, stroke, and hypertension due to damaged blood vessels and increased cholesterol levels.
- Diabetic Foot Ulcers and Infections: Poor circulation and nerve damage lead to slow-healing wounds, which can become infected and may require amputation if untreated.
6. Prevention and Lifestyle Modifications
Type 1 Diabetes Prevention
Currently, there is no known way to prevent Type 1 diabetes, but research suggests that avoiding certain viral infections and maintaining a healthy immune system may help delay onset in at-risk individuals.
Type 2 Diabetes Prevention
- Healthy Diet: Eating whole grains, lean proteins, fiber-rich foods, and reducing sugar and processed foods can help regulate blood sugar levels.
- Regular Physical Activity: Engaging in at least 150 minutes of moderate-intensity exercise per week can improve insulin sensitivity.
- Maintain a Healthy Weight: Losing 5-10% of body weight significantly reduces diabetes risk.
- Monitor Blood Sugar Levels: Regular screening for prediabetes helps in early intervention.
- Manage Stress: High stress levels contribute to insulin resistance; mindfulness, yoga, and relaxation techniques can help.
- Adequate Sleep: Poor sleep can affect glucose metabolism and increase diabetes risk.
- Avoid Smoking and Limit Alcohol Consumption: Smoking increases insulin resistance, and excessive alcohol can spike blood sugar levels.
Gestational Diabetes Prevention
- Pre-Pregnancy Weight Management: Maintaining a healthy weight before conception reduces gestational diabetes risk.
- Healthy Eating Habits: Following a balanced diet throughout pregnancy can help regulate blood sugar.
- Regular Exercise: Light physical activity like walking or prenatal yoga can improve insulin sensitivity.
- Monitor Blood Sugar Levels: Routine glucose testing during pregnancy ensures early detection and management.