Definition & Core Problem
Source: Cleveland Clinic / NIHDiabetes mellitus is a chronic, metabolic disease characterized by elevated levels of blood glucose (hyperglycemia). It results from defects in insulin secretion, insulin action, or both.
Key Hormone: Insulin, produced by the pancreas, acts as a "key" that allows glucose from the bloodstream to enter cells for energy.
Mechanism (Pathophysiology)
Source: Mayo Clinic / YouTube Medical- Glucose Build-up: Without functional insulin, glucose cannot enter cells and builds up in the blood.
- Insulin Resistance: Common in Type 2; cells in muscles, fat, and liver ignore insulin signals.
- Beta-Cell Dysfunction: The immune system may destroy insulin-producing cells (Type 1) or they may "burn out" over time (Type 2).
- Ketosis: When cells lack glucose, the body breaks down fat, releasing acidic ketones into the blood.
Signs and Symptoms
Source: NIH / Mayo Clinic- Polyuria: Frequent urination.
- Polydipsia: Increased thirst and dry mouth.
- Polyphagia: Excessive hunger, even after eating.
- Fatigue: Extreme tiredness.
- Vascular Changes: Blurred vision and slow-healing sores.
- Neuropathy: Numbness or tingling in hands and feet.
Types of Diabetes
Source: Diabetes UKType 1: Autoimmune destruction of beta cells; requires daily insulin.
Type 2: Most common; linked to genetics and lifestyle; involves insulin resistance.
Gestational: Occurs during pregnancy; increases future risk of Type 2.
Prediabetes: Elevated sugar levels that do not yet meet the diagnostic threshold for Type 2.
Common Complications
Source: Mayo Clinic- Retinopathy: Potential blindness via eye damage.
- Nephropathy: Kidney damage leading to renal failure.
- Cardiovascular Disease: Significantly higher risk of heart attack and stroke.
- Foot Damage: High risk of infections/ulcers often resulting in amputation.