Excellence in Kidney care, Compassion at the core
Providing contemporary, evidence-based nephrology care across the Central Coast and Sydney with more nearly 25 years of specialist expertise.
Welcome to Two Kidneys
Expert kidney care with genuine compassion
Dr Karthik Kumar is a nephrologist with over 25 years of experience in nephrology, dialysis, and transplantation, trained at PGIMER and Westmead Hospital. He serves as Senior Nephrologist within the Central Coast Local Health District.
Dr Kumar has cared for more than 10,000 patients across the Central Coast and Sydney, currently supporting over 65 dialysis patients across five units. His mission is to deliver expert, accessible, and compassionate care that empowers patients and their families.
- Acute & Chronic Kidney Disease
- Dialysis & Transplantation
- Hypertension & Renovascular Disease
- Glomerulonephritis & Diabetic Nephropathy
- Pregnancy-related Kidney Issues
- Geriatric Nephrology & Electrolyte Disorders
Years of specialist nephrology experience
Patients cared for across Central Coast & Sydney
Dialysis patients currently supported
We care for your kidneys and your overall wellbeing
From acute kidney disease to complex transplantation, dialysis and hypertension Dr Karthik Kumar brings ethical, evidence-based care centred entirely on you.
What We Treat
Comprehensive kidney care for every stage of your health journey
Chronic Kidney Disease
Personalised management of CKD at every stage — slowing progression, protecting your quality of life, and planning ahead.
Dialysis Care
Comprehensive haemodialysis and peritoneal dialysis support across five units, including our Green Dialysis initiative for sustainable care.
Kidney Transplantation
Pre- and post-transplant assessment and management, ensuring the best possible outcomes for transplant recipients.
Hypertension
Expert diagnosis and treatment of high blood pressure and related kidney conditions, including renovascular disease.
Glomerulonephritis
Specialist care for inflammatory kidney conditions, using evidence-based immunosuppressive and supportive therapies.
Diabetic Kidney Disease
Targeted management of kidney complications arising from diabetes, including cardiorenal protection strategies.
Genetic Kidney Disease
Expert management for inherited renal disorders with a focus on personalized monitoring and long-term family care.
Acute Kidney Injury
Urgent, intensive treatment for sudden kidney function loss, aimed at rapid stabilization and recovery.
Renal Stone Disease
Advanced diagnosis and treatment for kidney stones, including effective strategies to prevent future recurrence.
Kidney Biopsy
Precision-guided tissue sampling for accurate diagnosis of complex kidney conditions and tailored treatment planning.
Renal Biopsy Information
Detailed patient guidance and support to help you understand the biopsy procedure and ensure your comfort.
Point-of-Care Ultrasound
Rapid, real-time imaging of the kidneys and urinary tract for immediate diagnostic assessment and decision-making.
24-Hour Urine Collection
Comprehensive analysis of urine over a full day to detect metabolic issues and prevent future kidney stone formation.
24-Hour Ambulatory BP
Advanced monitoring of blood pressure patterns over a full day to guide effective hypertension management.
Evidence-based care for lasting kidney health
Dr Kumar integrates the latest clinical evidence with a deeply patient-centred approach — prioritising safety, transparency, and long-term wellbeing in every decision.
Easy way to get started
Expert kidney care is just an appointment away
Getting the right kidney care is simple. Dr Kumar and his team are here to guide you from your very first referral through to ongoing management.
Get a Referral
Ask your GP or specialist for a referral to Dr Karthik Kumar to access Medicare rebates and continuity of care.
Book Your Appointment
Contact our rooms to schedule a convenient time at Gosford, Wyong, or Sydney Adventist Hospital, or request telehealth.
Attend Your Consultation
Bring your referral, Medicare card, medication list, and recent test results. Arrive 10–15 minutes early.
Receive Your Care Plan
Dr Kumar will review your history, order any necessary investigations, and create a personalised kidney care plan for you.
Why Choose Dr Karthik Kumar
We are committed to excellent kidney care
With over 25 years of specialist expertise, admitting rights at four hospitals, and a patient-first philosophy, Dr Kumar delivers care that is ethical, contemporary, and genuinely compassionate.
MBBS, MD, DNB, DM, FRACP, AFRACMA — trained at PGIMER and Westmead Hospital with over 25 years of specialist experience.
Admitting and consulting rights at Gosford Public, Gosford Private, Wyong, and Sydney Adventist Hospitals.
Dr Kumar's 10/90 principle - 10% books, 90% listening to patients ensures every treatment plan truly fits your life.
Make Appointment
Put a kidney specialist in your schedule for a healthier future
Dr Karthik Kumar consults at Gosford, Wyong, and Sydney Adventist Hospitals. Telehealth appointments are also available for suitable follow-up consultations.
Please ask your GP or specialist for a referral to access Medicare rebates.
02 4321 0555
02 4321 0125
Patient Stories
Results that speak for themselves
Hear from patients across the Central Coast and Sydney who have experienced Dr Kumar’s compassionate, expert kidney care.