Medical Encyclopaedia › Type 2 diabetes (short definition)
In brief: Type 2 diabetes is the most common form of diabetes. The body’s cells respond less well to insulin, and in the long run the pancreas cannot meet the increased demand. Blood sugar therefore remains raised and damages blood vessels and nerves over time.
Causes and risk factors
Important risk factors are overweight, especially abdominal fat, lack of exercise, a family predisposition and older age. A history of gestational diabetes and certain medicines also increase the risk. It usually begins with insulin resistance; so-called prediabetes can be present for years before diagnosis.
Symptoms
Type 2 diabetes develops gradually and often goes unnoticed for a long time. Possible signs are increased thirst, frequent urination, tiredness, poorly healing wounds and frequent infections. Many diagnoses are made by chance during routine examinations.
Diagnosis
The diagnosis is based on blood values: a fasting blood sugar of 126 mg/dl or more, an HbA1c of 6.5 per cent or more, or a raised value in the oral glucose tolerance test. HbA1c reflects the average blood sugar over the last two to three months.
Treatment
The basis is a change in lifestyle with a balanced diet, regular exercise and weight loss if needed. If this is not enough, metformin is usually the first medicine. Depending on associated conditions, SGLT2 inhibitors or GLP-1 receptor agonists are added, which can also protect the heart and kidneys. Later, insulin may become necessary. Treatment goals are set individually.
Preventing complications
Persistently raised blood sugar can damage the eyes, kidneys, nerves and blood vessels and increase the risk of heart attack and stroke. Regular checks of the back of the eye, kidney values and feet, and treatment of high blood pressure and lipid disorders, are therefore important.
Related terms in the encyclopaedia
Insulin resistance, HbA1c, Metformin, Blood sugar, Diabetic foot, Diabetic polyneuropathy, Blood glucose meter
Further reading on Medizin Aktuell
Sources
- Bundesärztekammer, KBV, AWMF: Nationale VersorgungsLeitlinie Typ-2-Diabetes, leitlinien.de
- Deutsche Diabetes Gesellschaft (DDG): Praxisempfehlungen
- IQWiG: gesundheitsinformation.de – Gesundheitsinformationen des Instituts für Qualität und Wirtschaftlichkeit im Gesundheitswesen
Note: This article is for general information and does not replace advice, diagnosis or treatment from a doctor or pharmacist. Last updated: October 2026.