Diabetes is a disease in which blood glucose is too high. Insulin, a hormone made by the pancreas, helps glucose enter cells for energy. Diabetes develops when the body makes little or no insulin, or does not use insulin effectively.

Main types

The National Institute of Diabetes and Digestive and Kidney Diseases describes three common types. In type 1 diabetes, the immune system destroys insulin-producing cells, so daily insulin is required. In type 2 diabetes, cells do not use insulin properly and the pancreas may not make enough. Gestational diabetes develops during pregnancy and increases later type 2 diabetes risk.

Symptoms and diagnosis

Possible symptoms include increased thirst, frequent urination, fatigue, blurred vision and unexplained weight loss. Some people, particularly with type 2 diabetes, have few symptoms. Diagnosis requires validated blood tests; symptoms or a home reading alone are not enough.

Management

Treatment depends on diabetes type, blood-glucose pattern and individual health. It may include insulin, other medicines, nutrition planning, physical activity and monitoring. People with diabetes also need appropriate checks for blood pressure, cholesterol, eye, kidney, nerve and foot health.

Type 1 diabetes cannot currently be prevented. Type 2 risk can sometimes be reduced through sustainable activity, nutrition and weight-management measures, but genetics and other factors also matter. Prescribed medicine should not be stopped or changed without clinical advice.