Hypoglycemia (Hypoglycemia) refers to a drop in blood sugar levels below the normal range. Clinically, values below 70 mg/dl (3.9 mmol/l) are considered to be a situation in which glucose supply is necessary.
Etiology and triggers
Hypoglycemia occurs due to an imbalance between the amount of insulin and glucose requirements. Common causes are:
- Overdose of insulin or blood sugar-lowering medications (e.g. sulfonylureas)
- Increased glucose consumption through physical activity
- Skipped meals or insufficient carbohydrate intake
- Alcohol consumption, which hinders the production of new sugar in the liver
Classification of symptoms
| Category | Pathophysiology | Key symptoms |
|---|---|---|
| Adrenergic | Activation of the autonomic nervous system (early warning signs) | Trembling, sweating, racing heart, palpitations, cravings |
| Neuroglycopenic | Direct glucose deficiency in the central nervous system | Difficulty concentrating, visual disturbances, speech problems, confusion, coordination problems |
Severity levels and intervention thresholds
- Mild hypoglycemia (stage 1): Blood sugar 54-70 mg/dl. The person affected can react themselves.
- Moderate hypoglycemia (stage 2): Blood sugar below 54 mg/dl. Significant symptoms possible.
- Severe hypoglycemia (stage 3): Severe impairment of orientation. External assistance (e.g. glucagon or intravenous glucose) is required.
Acute management (15-15 rule)
To treat mild hypoglycemia, the following protocol is recommended:
- Feed: Consume 15-20 g of readily available carbohydrates (e.g. dextrose or glucose in liquid form).
- Latency: Waiting time of 15 minutes to wait for the glucose to be absorbed.
- Re-evaluation: Blood glucose measurement again; If the values remain low, repeat the application.
Long-term complications
Repeated hypoglycemia can lead to Hypoglycemia unawareness disorder in which the early warning symptoms do not occur and severe symptoms occur immediately.
Further information:
→ Diabetes mellitus – knowledge and overview
→ Why hyporest
Sources
- German Diabetes Society (DDG). S3 guideline “Hypoglycemia”. 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
