Type 2 diabetes is a common chronic condition in which the body does not use insulin effectively and blood sugar levels remain elevated. It is classified as a metabolic disorder and typically develops over years. While it often appears in adults, it increasingly affects younger people. Long-term high blood sugar is associated with damage to blood vessels and nerves.
Causes and mechanism
The condition arises from a combination of insulin resistance in tissues and a relative deficiency in insulin production by the pancreas. Genetic predisposition, excess body weight, sedentary lifestyle and aging are important contributors. Metabolic changes affect how the body stores and uses glucose and fats.
Signs, diagnosis and presentation
Symptoms can be subtle at first and include increased thirst, frequent urination, fatigue, blurred vision and slow wound healing. Diagnosis is made by measuring raised levels of blood glucose on fasting, after a glucose challenge, or by a long-term marker. Screening is recommended for people with risk factors.
Management, complications and prevention
- Management emphasizes lifestyle measures (weight loss, healthy eating, regular physical activity) and, when needed, medications that improve insulin sensitivity or lower glucose.
- Complications result from chronic high glucose and include cardiovascular disease such as heart attacks and strokes, eye damage progressing to blindness, and progressive kidney injury that can lead to kidney failure.
- Regular monitoring and treating blood pressure and cholesterol reduce risk of long-term harm.
History and public health importance
Recognized as distinct from insulin-deficient diabetes in the 20th century, type 2 diabetes has grown with global changes in diet, activity and lifespan. It is a major driver of illness and health-care use worldwide. Early detection, population prevention strategies and equitable access to care are central to reducing its impact.