Diabetes mellitus is a chronic metabolic disease in which the body can no longer adequately regulate blood sugar levels. It is characterized by a permanently elevated blood sugar level (Hyperglycemia), which is caused by an absolute or relative deficiency of the hormone Insulin or a disturbed insulin effect occurs.
Main forms of diabetes mellitus
| shape | main cause | Typical age group | share |
|---|---|---|---|
| Type 1 diabetes | Autoimmune-related destruction of insulin-producing beta cells (absolute insulin deficiency) | Children, teenagers and young adults | approx. 5–10% |
| Type 2 diabetes | Insulin resistance of the body's cells combined with increasing insulin deficiency | Middle to older age | approx. 90% |
| Gestational diabetes | Temporary insulin resistance caused by pregnancy hormones | Pregnant women | variable (approx. 5–10% of all pregnancies) |
Causes
- Type 1 diabetes: Genetic predisposition in combination with triggering environmental factors that trigger an autoimmune reaction against the beta cells of the pancreas.
- Type 2 diabetes: Multifactorial - genetic predisposition, obesity, lack of exercise and long-term unfavorable eating habits play the biggest role.
- Gestational diabetes: Hormonal changes during pregnancy that lead to temporary insulin resistance.
Symptoms
Typical signs of untreated or poorly controlled diabetes mellitus are:
- Severe thirst (polydipsia) and frequent urination (polyuria)
- Fatigue and loss of performance
- Vision problems
- Delayed wound healing
- Frequent infections (e.g. urinary tract infections or fungal infections)
- Weight loss despite normal or increased food intake (especially in type 1 diabetes)
Diagnostics
Diagnosis is made through laboratory tests:
- Fasting blood sugar
- Oral glucose tolerance test (OGTT)
- HbA1c value (long-term blood sugar from the last 2-3 months)
Therapy
Treatment depends on the form and severity of the disease and usually includes:
- Lifestyle measures (diet, exercise, weight loss)
- Medication (for type 2 diabetes)
- Insulin therapy (always for type 1 diabetes, if necessary for type 2 diabetes)
- Regular blood sugar monitoring (self-measurement or CGM systems)
Further information:
→ Diabetes mellitus – knowledge and overview
→ Why hyporest
Sources
- German Diabetes Society (DDG). S3 guideline “Diabetes mellitus type 1 and type 2”. As of 2025. Available at: www.deutsche-diabetes-gesellschaft.de/leitlinien.
- American Diabetes Association. Standards of Medical Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1). Available at: diabetesjournals.org.
- Robert Koch Institute (RKI). Federal health reporting – diabetes mellitus in Germany. Berlin 2024.
- International Diabetes Federation (IDF). IDF Diabetes Atlas. 11th edition. Brussels 2025. Available at: diabetesatlas.org.
Important note:
The information in this encyclopedia article is intended solely for general and non-binding information. They do not replace medical advice, diagnosis or therapy. If you have any health questions or complaints, please always consult a doctor or qualified healthcare professional. The content was created with the greatest possible care, but errors cannot be completely ruled out.
Last updated: February 26, 2026
