What is the Kidney Function test?

The Kidney Function blood test assesses how effectively the kidneys are filtering waste products and maintaining fluid and electrolyte balance. It focuses on three core markers that reflect kidney performance and filtration capacity.

This panel includes:

• Urea – a waste product from protein metabolism
• Creatinine – a muscle breakdown product filtered by the kidneys
• eGFR (estimated Glomerular Filtration Rate) – a calculated measure of kidney filtration efficiency

Together, these markers provide a clear picture of renal function, helping identify acute or chronic kidney impairment.

Why do I need a Kidney Function test?

Kidney disease often develops silently and may only cause symptoms in advanced stages. Early testing allows detection before permanent damage occurs.

You may need a Kidney Function test if you:

• Have diabetes or high blood pressure
• Experience swelling in legs or ankles
• Have fatigue or reduced urine output
• Take medications affecting kidney function
• Have a family history of kidney disease
• Are undergoing routine health screening
• Need monitoring for chronic kidney disease (CKD)

Symptoms associated with kidney dysfunction include:

• Fatigue
• Swelling (oedema)
• Changes in urination
• Shortness of breath
• Nausea
• Confusion (advanced cases)

Benefits of the Kidney Function test

• Detects kidney impairment early
  Identifies reduced filtration before symptoms appear.
• Assesses kidney filtration capacity
  eGFR reflects overall renal performance.
• Monitors chronic kidney disease
  Tracks progression or stability over time.
• Supports medication safety
  Ensures drugs are dosed appropriately.
• Essential for diabetes and hypertension care
  Protects long-term kidney health.
• Clinically standard renal panel
  Used routinely in primary and specialist care.
• Simple blood test
  Requires only one sample.
• Supports preventive healthcare
  Enables early intervention and lifestyle changes.

Step by step – how the test works

You can access Kidney Function testing UK-wide through two options:

1. Clinic appointment
   Attend your nearest UK clinic where a healthcare professional will take your blood sample.
2. At-home or hotel visit (£60 extra)
   A qualified phlebotomist comes to your home or hotel, so you don’t need to travel.

Your sample is analysed in an accredited UK laboratory and eGFR is calculated using standard equations.

Your results explained

Low kidney function

• Raised creatinine
• Raised urea
• Reduced eGFR

Typical UK interpretation:

• eGFR < 60 mL/min/1.73m²

Normal kidney function

• Balanced urea and creatinine
• Normal filtration rate

Typical UK interpretation:

• eGFR ≥ 90 mL/min/1.73m²

Moderately reduced kidney function

• Mild elevation in waste products

Typical UK interpretation:

• eGFR 60–89 mL/min/1.73m²

Results should be interpreted in relation to age, muscle mass and clinical context.