The diabetic nephropathy is damage to the kidneys caused by long-term elevated blood sugar levels. It is one of the most serious long-term complications of diabetes and is the most common cause of kidney failure requiring dialysis in the Western world.
Causes and risk factors
The disease occurs due to damage to the small blood vessels and filter units (glomeruli) in the kidney. Important risk factors are:
- Long duration of diabetes
- Poor long-term blood sugar control (high HbA1c)
- High blood pressure
- Smoking
- Genetic predisposition
- Obesity and lipid metabolism disorders
Stadiums
| stage | Description | Albumin in urine |
|---|---|---|
| Stage 1 (hyperfiltration) | Increased filter performance of the kidneys | normal |
| Stage 2 (microalbuminuria) | Early damage – low protein excretion | 30-300 mg/24 hours |
| Stage 3 (macroalbuminuria) | Clinically manifest nephropathy | > 300 mg/24 h |
| Stage 4 (renal insufficiency) | Decreasing kidney function | greatly increased |
| Stage 5 (end-stage renal failure) | Dialysis or transplant necessary | very much increased |
Symptoms
Usually asymptomatic in the early stages. Later occur:
- Swelling of the legs and feet (edema)
- High blood pressure
- Foamy urine (protein excretion)
- Fatigue and loss of performance
- In the final stage: nausea, itching, shortness of breath
Diagnostics
Regular screening is crucial:
- Urinary albumin-creatinine ratio (ACR)
- eGFR (estimated glomerular filtration rate) from blood
- Regular blood pressure and blood sugar checks
Therapy and prevention
The best prevention is good blood sugar and blood pressure control. For advanced nephropathy:
- Blood pressure lowering medications (ACE inhibitors or AT1 blockers)
- Strict blood sugar control
- Protein-reduced diet
- In case of end-stage renal failure: dialysis or kidney transplant
Further information:
→ Diabetes mellitus – knowledge and overview
→ Why hyporest
→ Diabetic retinopathy
Sources
- German Diabetes Society (DDG). S3 guideline “Diabetic nephropathy”. 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
