Kidney disease develops when the kidneys fail to function properly, typically resulting from damage to the nephrons that compromises their ability to filter waste and fluids from the body.
Classifications of Kidney Disease
- Acute Renal Failure (ARF): Occurs rapidly, often due to injury, significant blood loss, or exposure to harmful substances or medications. While it may cause lasting kidney damage, recovery is possible if the kidneys remain largely intact.
- Chronic Kidney Disease (CKD): Develops gradually when kidneys cannot effectively remove toxins and waste. The progression can be managed and slowed with proper treatment.
- End Stage Renal Disease (ESRD): Represents severe, irreversible kidney function loss requiring dialysis or transplantation for survival.
Causes of Chronic Kidney Disease
Diabetes and high blood pressure represent the primary causes of CKD:
- Diabetes: When glucose remains in the bloodstream rather than being metabolized, it damages nephrons — a condition termed diabetic nephropathy. Maintaining controlled glucose levels can delay or prevent this damage.
- High blood pressure: Damages kidney blood vessels. ACE inhibitors and ARBs offer superior kidney protection compared to other blood pressure medications.
Additional causes include:
- Autoimmune, infectious, and sclerotic diseases attacking kidney blood vessels, often detected through protein or blood in urine
- Inherited conditions like polycystic kidney disease (PKD), where cysts progressively replace kidney tissue
Symptoms
Kidney disease is called "the silent disease" because early stages typically produce no noticeable symptoms. Later signs include:
- Difficulty concentrating
- Swelling in legs, hands, or face
- Itchy skin
- Insomnia
- Shortness of breath
- Nausea, poor appetite, vomiting
- Weakness and fatigue
Kidney Function Tests
- Proteinuria screen: Urine test detecting abnormal protein presence, indicating leaky kidney filters
- Serum creatinine: Blood test measuring creatinine levels; elevated results suggest impaired kidney function
- Creatinine clearance: Combined urine and blood test assessing kidney filtration efficiency
- Blood urea nitrogen (BUN): Measures waste nitrogen; high levels indicate kidney dysfunction
- Renal imaging: Ultrasound, CT, or MRI revealing kidney structure and potential abnormalities
- Renal biopsy: Needle extraction of kidney tissue for microscopic examination
CKD Stages and Treatment
Glomerular Filtration Rate (GFR) represents the best indicator of kidney function. The National Kidney Foundation established five CKD stages based on declining GFR:
| Stage | Description | Treatment Approach |
|---|---|---|
| 1 | Kidney damage with normal function | Slow CKD progression; reduce cardiovascular disease risk |
| 2 | Kidney damage with mild function decline | Estimate and manage CKD progression |
| 3 | Kidney damage with moderate function decline | Address anemia and bone health complications |
| 4 | Kidney damage with severe function decline | Manage complications; prepare for dialysis or transplant |
| 5 | Complete kidney failure | Dialysis, transplantation, or palliative care |
Managing and Slowing Progression
Early detection enables timely intervention. Several strategies can slow disease advancement:
- Control diabetes: Maintaining near-normal blood sugar significantly reduces kidney failure risk
- Manage blood pressure: Target 130/85 mmHg through diet and/or medication
- Treat anemia: Address low red blood cell counts that contribute to fatigue and heart complications
- Optimize diet and exercise: Adjust nutrition as disease progresses under medical guidance
- Avoid nephrotoxic medications: Certain pain relievers like aspirin, ibuprofen, and naproxen worsen kidney disease