Hemodialysis is a life-sustaining treatment that performs the job of failing kidneys — filtering waste products, excess fluid, and toxins from the blood. During hemodialysis, blood is pumped out of the body through a special access point, passed through a dialyzer (artificial kidney) that cleans it, and returned to the body. It is the most common form of dialysis worldwide and keeps patients alive when their kidneys can no longer function.
How Does Hemodialysis Work?
The dialyzer contains thousands of tiny semi-permeable membranes called hollow fibers. Blood flows through these fibers while dialysis fluid (dialysate) flows around them in the opposite direction. Waste products like urea, creatinine, and potassium diffuse from the blood into the dialysate, while the cleaned blood is returned to the body. This process typically takes 3-4 hours per session.
Vascular Access: AV Fistula vs Catheter
AV Fistula (Preferred)
A surgeon connects an artery directly to a vein, usually in the forearm. The fistula matures over 6-8 weeks, creating a strong, high-flow access that lasts for years. It has the lowest infection and clotting rates.
Best for: Long-term dialysis patients
Permacath (Temporary Catheter)
A dual-lumen catheter is placed in a large vein (usually jugular or femoral). It can be used immediately but carries higher infection risk. Used as a bridge while waiting for an AV fistula to mature or for short-term dialysis.
Note: Not ideal for long-term use
Dialysis Schedule
Conventional Schedule
- 3 sessions per week (e.g., Mon-Wed-Fri or Tue-Thu-Sat)
- 4 hours per session
- Done at a dialysis centre
Nocturnal / Extended Dialysis
- 5-6 nights per week while sleeping
- 6-8 hours per session
- Better toxin removal, fewer dietary restrictions
What Happens During a Session?
Preparation
Your blood pressure and weight are checked. The access site is cleaned and connected to the dialysis machine.
Dialysis
Blood flows through the dialyzer at 200-400 ml/min. The machine monitors pressure, air bubbles, and clotting continuously. You can read, watch TV, or sleep.
Fluid Removal
The machine removes excess fluid based on your target dry weight. Your blood pressure is monitored throughout to prevent drops.
Completion
After 3-4 hours, blood is returned and the lines are disconnected. A bandage is applied. Your post-dialysis weight and BP are recorded.
Diet on Hemodialysis
Dialysis patients have specific dietary needs:
- •Potassium — restrict high-potassium foods (bananas, oranges, potatoes, tomatoes)
- •Phosphorus — limit dairy, nuts, cola, processed foods
- •Sodium — reduce salt intake to control thirst and fluid gain
- •Fluid — typically restricted to 500-1000 ml/day between sessions
- •Protein — increased protein intake (1.0-1.2 g/kg/day) to compensate for losses during dialysis
Side Effects
Home Hemodialysis
Home hemodialysis allows patients to perform dialysis in the comfort of their own home, typically with training from the dialysis team. Benefits include more flexibility, better blood pressure control, improved quality of life, and potentially better survival. Smaller, user-friendly machines make home dialysis increasingly accessible in India. Talk to Dr. Goel to see if you are a candidate.
Start Dialysis with Expert Guidance
Dr. Rajesh Goel provides comprehensive dialysis care — from vascular access creation to dialysis prescription and long-term management. He will help you choose the best dialysis modality for your lifestyle.