Chronic kidney disease and uremia
- Process
Once enough nephrons are lost, the survivors are overworked and fail too, and the end-stage kidney affects the whole body.
What it is
Chronic kidney disease is the common end of glomerular, tubulointerstitial, vascular and cystic disease. When nephrons are lost, the rest hypertrophy and raise their filtration, which injures podocytes and causes secondary FSGS; proteinuria injures tubules and drives interstitial fibrosis. The end-stage kidney is small and scarred, whatever the cause. Uremia affects blood, bone, heart, gut, nerves and skin, and dialysis kidneys develop acquired cysts.
Step by step
- A primary disease destroys a share of nephrons.
- The surviving nephrons enlarge and filter more under higher pressure (angiotensin II).
- Podocytes are stretched and lost: adaptive segmental sclerosis.
- Filtered proteins and inflammation injure tubules, which signal fibroblasts (TGF-β).
- Interstitial fibrosis and capillary loss make the kidney hypoxic, causing more injury.
- Function falls below the level that keeps the internal milieu stable: uremia.
Systemic effects of chronic kidney disease
| System | Effect | Why |
|---|---|---|
| Fluid and sodium | Edema, hypertension or dehydration | Poor control of salt and water excretion |
| Potassium and acid | Hyperkalemia, metabolic acidosis | Low potassium secretion and ammonium production |
| Blood | Anemia, bleeding | Low erythropoietin; platelet dysfunction from uremic toxins |
| Bone and minerals | Renal osteodystrophy, vascular calcification | High phosphate, low calcitriol, secondary hyperparathyroidism |
| Heart and vessels | Left ventricular hypertrophy, heart failure, pericarditis | Hypertension, volume overload, uremic toxins |
| Nerves, gut and skin | Neuropathy, encephalopathy, nausea, pruritus, sallow skin | Retained toxins, deposits of urochromes and calcium |
Clinical notes
- Diabetes and hypertension are the main causes in Colombia and worldwide; in Mesoamerica and other farming regions, a chronic interstitial nephropathy of unclear cause affects young agricultural workers.
- Cardiovascular disease is the leading cause of death in chronic kidney disease.
Test yourself
Think of the answer, then tap the question to see it.
Why does chronic kidney disease progress even after the original disease stops?
Surviving nephrons hyperfilter, which injures podocytes (secondary FSGS) and drives proteinuria and tubulointerstitial fibrosis.
What causes anemia in chronic kidney disease?
Reduced erythropoietin production by the damaged kidney, plus iron deficiency and shortened red cell survival.
Which lesion of the pericardium is typical of uremia?
Fibrinous pericarditis.
Elsewhere in DurgiPedia
- Physiology of acute and chronic kidney failure
- Erythropoiesis and erythropoietin
- Calcium regulation: PTH, vitamin D and calcitonin
- Fibrosis in organs: TGF-β and the myofibroblast
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Chronic Kidney Disease (StatPearls (NCBI Bookshelf), 2024).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.