Kidney Function

Authored by Chris McDermott, APRN, practicing with autonomous authority in Florida

Introduction

Kidney function plays a vital role in maintaining whole-body health. These small but powerful organs are responsible for filtering blood, removing metabolic waste, balancing fluid and electrolytes, regulating blood pressure, and supporting red blood cell production. When kidney function begins to decline—even subtly—many of these essential processes can be disrupted.
At Intercoastal Health, we utilize a functional medicine practitioner model that focuses on early detection, individualized intervention, and biomarker-based evaluation to support long-term kidney health. Whether you are experiencing symptoms, managing risk factors, or simply seeking preventative care, understanding your kidney function is an essential part of your wellness strategy.

What Is Kidney Dysfunction?

Kidney dysfunction refers to any decline in the kidneys’ ability to perform their core roles:

• Filtering blood and removing waste products (e.g., urea, Creatinine)
• Regulating sodium, potassium, calcium, and other electrolytes
• Maintaining fluid balance
• Producing hormones like erythropoietin (which supports red blood cell production) and renin (which helps control blood pressure)

   

When kidney function is impaired over time, it can lead to Chronic Kidney Disease (CKD) and potentially End-Stage Renal Disease (ESRD), which may require dialysis or kidney transplantation.

Recognizing the Symptoms

Early stages of kidney dysfunction are often silent. Many individuals may not experience noticeable symptoms until the disease is advanced. However, subtle clinical signs may appear as the body’s ability to regulate waste and fluid becomes compromised.
Common Signs and Symptoms:

• Fatigue and general weakness
• Swelling (edema) in the ankles, legs, or face
• Shortness of breath, especially with activity
• Changes in urination: Frequency, appearance, or volume (including cloudy, dark, or bloody urine)
• Strong-smelling urine
• Puffiness around the eyes, often noted upon waking
• High blood pressure (hypertension)
• Nausea, vomiting, or metallic taste in mouth
• Itchy skin, particularly when persistent or generalized
• Pain in the lower back or flank region
• History of kidney stones or urinary tract infections

   

These symptoms can overlap with other health conditions, making it critical to assess kidney biomarkers when there are clinical suspicions or risk factors present.

Functional Evaluation of Kidney Function

Functional medicine practitioners rely on a thorough evaluation of lab markers, symptom patterns, and lifestyle data to assess kidney function. At Intercoastal Health, our diagnostic approach integrates conventional and functional parameters to offer the most comprehensive insights possible.

1. Blood Tests
   • Serum Creatinine: A waste product from muscle metabolism; elevated levels may signal impaired kidney filtration.
   • BUN: Reflects protein metabolism and kidney excretion; increased levels may indicate decreased function or dehydration.
   • Estimated Glomerular Filtration Rate (eGFR): A calculated value using creatinine, age, and sex that estimates filtering capacity.
     • eGFR ≥90 mL/min/1.73 m² is considered normal
     • eGFR 60–89 may indicate early decline
     • eGFR <60 warrants further investigation
2. Urine Testing
   • Urinalysis: Screens for protein, blood, glucose, ketones, and infection.
   • Albumin-to-Creatinine Ratio (ACR): Detects early protein leakage—often one of the first signs of kidney dysfunction.
     • <30 mg/g is normal
     • 30–300 mg/g indicates microalbuminuria
     • 300 mg/g suggests macroalbuminuria
3. Imaging
   • Ultrasound: To assess kidney size, structural abnormalities, cysts, or obstruction.
   • CT or MRI: When additional anatomical detail is required.
4. Kidney Biopsy
   • In selected cases, particularly when autoimmune disease or glomerulonephritis is suspected.

      

Functional Medicine Lab Interpretation

Note: Ferritin is an acute-phase reactant and may be falsely elevated in inflammation—check C-Reactive Protein or ESR – Female for context.

Causes of Kidney Dysfunction

In functional medicine, identifying the root cause of dysfunction is key. Kidney disease often evolves over years, driven by metabolic, autoimmune, infectious, or toxic factors.
Primary Contributors:

• Diabetes: High glucose levels damage small vessels in the glomeruli, leading to diabetic nephropathy.
• Hypertension: Chronic high blood pressure strains renal vessels and impairs perfusion.
• Autoimmune Conditions: Lupus, IgA nephropathy, or vasculitis may cause inflammatory damage.
• Chronic Infections: Recurrent UTIs or systemic infections can lead to scarring.
• Obstruction: Kidney stones, tumors, or enlarged prostate can block urine flow and cause backpressure.
• Environmental and Medication Toxins: Heavy metals, solvents, NSAIDs, PPIs, contrast dyes, and some antibiotics can impair renal tissue.

   

Drug Effects on Kidney Function

Medications That May Impair Renal Function:

• NSAIDs (e.g., ibuprofen, naproxen): Reduce blood flow to the kidneys
• Proton Pump Inhibitors (e.g., omeprazole): Linked to chronic interstitial nephritis
• Certain antibiotics (e.g., aminoglycosides, vancomycin) in high doses
• Contrast dyes used in imaging

   

Medications That Support Renal Function (in certain cases):

• ACE inhibitors/ARBs: Help reduce proteinuria and slow CKD progression in diabetic nephropathy
• SGLT2 inhibitors (e.g., empagliflozin): Shown to reduce CKD progression in type 2 diabetes

   

Functional Medicine Approach to Kidney Health

At Intercoastal Health, we emphasize early intervention, root cause resolution, and long-term organ preservation.

1. Lifestyle and Dietary Interventions
   • Low-sodium, whole-foods diet
   • Adequate hydration with clean, filtered water
   • Limiting processed foods, excess protein, and phosphorus additives
   • Anti-inflammatory nutrition, rich in omega-3s, leafy greens, and antioxidants
   • Blood pressure optimization through mindfulness, movement, and magnesium support
2. Nutraceutical and Botanical Support
   • CoQ10: Supports mitochondrial and renal energy metabolism
   • N-acetylcysteine (NAC): Promotes glutathione production and detoxification
   • Curcumin and resveratrol: May reduce renal inflammation
   • Magnesium and potassium: Balanced levels support electrolyte harmony
   • Berberine or cinnamon: May help with glucose regulation
3. Toxin Avoidance and Detoxification Support
   • Minimize exposure to BPA, phthalates, pesticides, and industrial chemicals
   • Support liver-kidney synergy via diet, sweating, and gentle detox protocols
4. Monitoring and Follow-Up
   • Regular assessment of eGFR, ACR, and electrolytes
   • Blood pressure and glucose monitoring
   • Medication review to avoid nephrotoxic agents

      

Associated Conditions

Chronic kidney dysfunction often coexists with broader metabolic and cardiovascular risks.
Commonly Associated Conditions:

• Cardiovascular Disease: Shared risk factors like hypertension and diabetes
• Anemia: Due to reduced erythropoietin production
• Electrolyte Disorders: Especially hyperkalemia or hypocalcemia
• Bone Mineral Disorders: From phosphate imbalance and reduced vitamin D activation
• Cognitive Decline: Related to toxin buildup or vascular changes