What is Chronic Kidney Disease (CKD)?
 

Your kidneys are organs located on both sides underneath your rib cage. They connect to your bladder by two ureters. Their primary job is to filter waste products, excess water, and toxins from your blood to create urine, while also balancing electrolytes, regulating blood pressure, and producing hormones that keep your bones strong and make red blood cells.

Chronic Kidney Disease (CKD) means abnormalities of kidney structure or function have been present for at least 3 months. CKD may be identified by a persistently reduced eGFR or by evidence of kidney damage, such as increased albumin in the urine (A2 or A3), even when filtration remains normal.

Common Causes & Risk Factors
 

CKD can stem from various systemic or localized conditions:
 

• Systemic: diabetes, hypertension, atherosclerosis, systemic autoimmune diseases, systemic infections, drugs, amyloidosis, sarcoidoisis, drugs, lead, vasculitis, systemic sclerosis, polycystic kidney disease, Alport’s syndrome, Fabry’s disease
   

• Localized: proliferative glomerulonephritis, glomerulosclerosis, membranous nephropathy, minimal change disease, recurrent upper urinary-tract infections, obstructions, ANCA-associated renal limited vasculitis, fibromuscular dysplasia, renal dysplasia, medullary cystic disease
   

Warning Signs & Common Symptoms
 

Kidney disease may not present with any symptoms during the early stages.
 

• Swelling (Edema): Swelling of the feet, ankles, legs, hands, or around the eyes can occur from sodium and fluid retention and, in some kidney diseases, significant urinary protein loss.

• Fatigue & Weakness: CKD can cause anemia partly because damaged kidneys produce less erythropoietin (EPO), a hormone that stimulates red blood cell production.

• Changes in Urination: Foamy urine (a sign of protein leaking into the urine, called proteinuria), waking up multiple times at night to urinate (nocturia), or reduced urine output.

• Skin Changes: Itching caused by a buildup of waste products (uremia) and mineral imbalances (phosphorus and calcium) in the blood.

• Uremic Symptoms: Nausea, vomiting, loss of appetite, a metallic taste in the mouth, ammonia breath odor, or muscle cramps and twitching.

Diagnostics
 

• Urine Albumin-to-Creatinine Ratio (uACR) - Measures the amount of albumin in the urine along creatinine (which helps account for varying urine concentration). It helps identify kidney damage, classify CKD severity, and predict the risk of future kidney disease progression and cardiovascular complications. Persistent albuminuria greter than 3 months can indicate CKD even when eGFR remains normal.
  
  Temporary causes of elevated uACR should be excluded or the test repeated when appropriate. Transient elevations can occur after recent: strenuous exercise, acute illness, acute kidney injury, acute severe hyperglycemia, acute severe hypertension, acute heart failure, and menstrual blood contamination. For these reasons, a single elevated uACR generally does not establish CKD; persistent albuminuria or other evidence of kidney abnormality for at least 3 months is generally required to demonstrate chronic kidney disease.
  ​
  A1: <30 mg/g — normal to mildly increased
  A2: 30–300 mg/g — moderately increased
  A3: >300 mg/g — severely increased
   

• Glomerular Filtration Rate (GFR) - Measures how well your kidneys are filtering:
  
  G1: eGFR ≥90 — Normal or high filtration; CKD is present only if there is other evidence of kidney damage.
  G2: eGFR 60–89 — Mildly decreased filtration; CKD is present only if there is other evidence of kidney damage.
  G3a: eGFR 45–59 — Mild-to-moderately decreased filtration.
  G3b: eGFR 30–44 — Moderately-to-severely decreased filtration.
  G4: eGFR 15–29 — Severely decreased filtration.
  G5: eGFR <15 — Kidney failure.
   

• Renal Ultrasound or CT: To look at the physical size and shape of the kidneys, check for blockages, cysts, or signs of scarring (shrunken, scarred kidneys point to chronic disease, while normal or large kidneys can sometimes point to acute injury or specific conditions like diabetic nephropathy or PKD).
   

• Kidney Biopsy: In select cases where the exact cause of kidney decline is unclear.

Management & Treatment Strategies
 

• Nephrology Referral:
   

  • Referral is usually indicated in CKD stage 3b-4, but it is also recommended earlier if there is resistant hypertension, electrolyte disturbances, rapid decline, heavy proteinuria, specific or rare kidney disorders, or unclear etiology. 
     

• Blood Pressure & Blood Sugar Control:
   

  • ACE Inhibitors or ARBs: Lower pressure inside the kidney's filtering units and reduce protein leakage into the urine.

  • SGLT2 Inhibitors: Can help protect both diabetic and non-diabetic kidneys, significantly slowing CKD progression.

  • Diuretics: Reduce extra fluid which can lower blood pressure

  • Glycemic Control: Keeping HbA1c targets optimized for individuals with diabetes.
     

• Dietary Modifications:
   

  • Eating a wholesome, balanced diet. Avoiding excess salt, added sugars, and processed foods. Other specific modifications may be recommended based on electrolyte levels. 
     

• Treating Complications:
   

  • Anemia: CKD can reduce erythropoietin production and can also cause functional iron deficiency, in which stored iron is not adequately available for red blood cell production. Treatment may include oral or IV iron and, in selected patients, erythropoiesis-stimulating medications (ESAs).

  • Phosphate binders for high blood phosphorus levels.
     

• End-Stage Management:
   

  • Hemodialysis (filtering blood through an external machine), Peritoneal Dialysis (using the lining of the abdomen to filter blood at home), or a Kidney Transplant.

                                                                          References & Guidelines
 

• National Kidney Foundation (NKF). How to Classify CKD; Urine Albumin-Creatinine Ratio (uACR); Criteria for Chronic Kidney Disease.

• Kidney Disease: Improving Global Outcomes (KDIGO). 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease.

• National Kidney Foundation (NKF). Stages of Chronic Kidney Disease (CKD).