Kidney

The Human Kidney: Anatomy, Physiology, Disorders & Treatment Guide
1. Introduction
- The kidneys are vital organs responsible for filtering blood, removing waste, balancing electrolytes, and regulating blood pressure.
- Each person has two kidneys, located on either side of the spine.
- Common kidney disorders include chronic kidney disease (CKD), kidney stones, infections, and kidney failure.
2. Anatomy of the Kidney
- Location: Lower back, behind the abdominal organs.
- Structure:
- Cortex: Outer layer containing filtration units.
- Medulla: Inner region containing nephrons.
- Renal Pelvis: Collects urine before passing to the ureter.
- Nephrons (Functional Unit):
- Glomerulus: Filters blood.
- Tubules: Reabsorb nutrients and regulate water balance.
- Blood Supply:
- Renal Arteries: Deliver oxygen-rich blood.
- Renal Veins: Carry filtered blood back to circulation.
- Urinary Connection:
- Kidneys → Ureters → Bladder → Urethra.
3. Physiology of the Kidney
- Filtration:
- Removes waste (urea, creatinine) from the blood.
- Electrolyte & Fluid Balance:
- Regulates sodium, potassium, and calcium levels.
- Blood Pressure Regulation:
- Produces renin, which controls blood vessel constriction.
- Red Blood Cell Production:
- Releases erythropoietin (EPO) to stimulate bone marrow.
- Acid-Base Balance:
- Maintains pH by excreting hydrogen ions.
4. Common Disorders & Pathophysiology
A. Chronic Kidney Disease (CKD)
- Cause: Progressive loss of kidney function.
- Risk Factors: Diabetes, hypertension, obesity.
B. Kidney Stones (Nephrolithiasis)
- Cause: Hard deposits of calcium, oxalate, or uric acid.
- Risk Factors: Dehydration, high salt diet, genetics.
C. Acute Kidney Injury (AKI)
- Cause: Sudden loss of kidney function due to infection, shock, or toxicity.
- Risk Factors: Sepsis, dehydration, medication toxicity.
D. Urinary Tract Infection (UTI) & Pyelonephritis
- Cause: Bacterial infection affecting the bladder or kidneys.
- Symptoms: Fever, back pain, burning urination.
E. Polycystic Kidney Disease (PKD)
- Cause: Genetic disorder leading to cyst formation in kidneys.
- Complications: Hypertension, kidney failure.
F. Kidney Cancer
- Common Type: Renal Cell Carcinoma.
- Risk Factors: Smoking, obesity, hypertension.
5. Signs & Symptoms of Kidney Disorders
- Early Symptoms:
- Fatigue, swelling in feet and hands.
- Frequent urination, foamy urine (proteinuria).
- Advanced Symptoms:
- High blood pressure.
- Muscle cramps, nausea, confusion.
- Red Flags:
- Blood in urine (hematuria).
- Sharp back pain (kidney stones).
- Severe swelling or sudden weight gain.
6. When to See a Doctor
- Persistent swelling, fatigue, or high blood pressure.
- Changes in urination (color, frequency, pain).
- Unexplained back pain or fever.
7. Emergency Signs Requiring Immediate Care
- Sudden loss of urination (kidney failure).
- Severe flank pain with vomiting (kidney stones).
- High fever with chills (kidney infection).
8. Diagnostic Process
- Clinical Examination: Blood pressure, swelling assessment.
- Laboratory Tests:
- Serum Creatinine & BUN: Kidney function markers.
- eGFR (Glomerular Filtration Rate): Measures kidney efficiency.
- Urine Analysis: Detects protein, blood, infection.
- Imaging Tests:
- Ultrasound: Detects kidney size, cysts, or stones.
- CT Scan: Detailed imaging for stones or cancer.
- Renal Biopsy: Identifies kidney disease progression.
9. Likely Diagnoses
- Chronic Kidney Disease (CKD).
- Kidney Stones.
- Acute Kidney Injury (AKI).
- Polycystic Kidney Disease.
- Urinary Tract Infection (UTI).
10. Treatment Options
A. Medications
- For CKD & High Blood Pressure:
- ACE Inhibitors (Lisinopril, Ramipril).
- Diuretics (Furosemide) for fluid control.
- For Kidney Stones:
- Pain Relief (Ibuprofen, Acetaminophen).
- Alpha-Blockers (Tamsulosin) to ease stone passage.
- For UTIs:
- Antibiotics (Ciprofloxacin, Nitrofurantoin).
- For Anemia in CKD:
- Erythropoietin (EPO) injections.
- For Kidney Cancer:
- Targeted Therapy (Sunitinib, Sorafenib).
- Approximate Medication Costs (USD):
- ACE Inhibitors: $10–$50/month.
- Diuretics: $5–$50/month.
- Painkillers for Stones: $10–$100.
- Antibiotics for UTIs: $20–$100 per course.
- EPO Injections: $200–$500 per dose.
B. Surgical/Procedural Interventions
- Dialysis (For Kidney Failure) ($300–$5,000 per session).
- Kidney Transplant (For End-Stage CKD) ($100,000–$300,000).
- Lithotripsy (Shock Wave Therapy for Stones) ($5,000–$10,000).
- Nephrectomy (Kidney Removal for Cancer) ($20,000–$50,000).
C. Lifestyle Modifications & Home Remedies
- For CKD Prevention:
- Low sodium, potassium diet.
- Adequate water intake (but not excessive).
- For Kidney Stones:
- Drink at least 2–3 liters of water daily.
- Reduce salt and oxalate-rich foods (spinach, nuts).
- For UTI Prevention:
- Urinate after intercourse.
- Cranberry supplements.
11. Precautions & Prevention
- Control Blood Pressure & Blood Sugar.
- Limit Painkiller Use: NSAIDs can harm the kidneys.
- Stay Hydrated: Prevents kidney stones and infections.
- Get Regular Kidney Function Tests: If at risk.
12. Prognosis & Recovery
- CKD: Progressive but manageable.
- Kidney Stones: Usually pass naturally; large ones require treatment.
- Kidney Infections: Fully treatable with antibiotics.
- Kidney Cancer: Prognosis depends on early detection.
13. Cost of Treatment
- Kidney Function Tests: $100–$500.
- Dialysis (Per Session): $300–$5,000.
- Kidney Transplant: $100,000–$300,000.
- Kidney Stone Surgery: $5,000–$20,000.
14. Frequently Asked Questions (FAQs)
- How can I improve kidney function?
- Stay hydrated, reduce salt and protein intake, manage blood pressure.
- What foods are bad for the kidneys?
- Excess salt, red meat, processed foods, alcohol.
- Can kidney disease be reversed?
- CKD is not reversible but can be slowed with treatment.
- What is the best treatment for kidney stones?
- Hydration, pain relief, lithotripsy for large stones.
- How do I prevent kidney infections?
- Good hydration, proper hygiene, treating UTIs early.
- Is dialysis a permanent solution?
- No, a kidney transplant is the only permanent cure for kidney failure.
- Can kidney stones be dissolved naturally?
- Some can, but large stones may require medical treatment.
- What is the life expectancy with kidney failure?
- With dialysis: 5–10 years on average.
- With transplant: 10–20+ years.