Understanding The Different Types Of Dialysis

• Written by Leena Khowal

  Reviewed by Ritika Malik

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When your kidneys can’t do their job of filtering waste and extra fluid, dialysis steps in as a life-saving support system. But did you know there’s more than one way to do dialysis? Yes, the treatment isn’t one-size-fits-all. Depending on your health, lifestyle, and doctor’s advice, you may be offered different types of dialysis. Each type has its own process, benefits, and challenges.

In this blog, we’ll walk you through what dialysis really means and explore the primary types—hemodialysis, peritoneal dialysis, and continuous renal replacement therapy (CRRT). We’ll explain how they work in simple terms, what to expect, and how each option can fit into your life. Whether you’re a patient, a caregiver, or simply curious, this guide will provide you with a clear understanding of dialysis and help you navigate your options.

What Is Dialysis?

Think of your kidneys as natural filters. They clean your blood, remove excess fluid, and maintain your body's balance. But when kidneys fail, waste and fluid start building up in the body—and that’s where dialysis steps in.

• Dialysis = artificial kidney support
• It removes waste products (like urea, creatinine)
• Controls fluid balance in your body
• Keeps salts and electrolytes stable
• Helps people with kidney failure survive and live better

Sometimes dialysis is temporary (after an injury), and other times it becomes long-term (for chronic kidney disease).

Types Of Dialysis

There are several methods for performing dialysis. The main ones are:

• Hemodialysis (HD) – Blood is cleaned using a dialysis machine and a filter.
• Peritoneal Dialysis (PD) – The lining of your abdomen acts as the filter.
• Continuous Renal Replacement Therapy (CRRT) – Mostly used in hospital ICUs for extremely sick patients.

Hemodialysis

Hemodialysis is like sending your blood to a washing machine and then bringing it back clean.

Here’s how it works:

• Access point: Doctors create a route for withdrawing blood and returning it to the body.

1. AV fistula: joins an artery and a vein (most preferred).
2. AV graft: uses a small tube if the veins aren’t suitable.
3. Catheter: a temporary tube in a large vein.

• Dialyser (artificial kidney):

1. Blood passes through a filter with tiny pores.
2. Waste products and excess fluid are removed into a cleansing fluid called dialysate.
3. Clean blood returns to the body.

• Ultrafiltration: Extra water is pulled out to reduce swelling and maintain your “dry weight.”
• Sessions:

1. Usually 3 times a week
2. Each session lasts about 3–5 hours.
3. It can be done in hospitals, dialysis centres, or sometimes at home.

Benefits Of Hemodialysis

• Cleans blood efficiently.
• Removes extra fluid and helps control blood pressure.
• Supervised by trained medical staff in centres.
• Long track record—widely used and trusted.

Challenges Of Hemodialysis

• Regular hospital or centre visits (can feel time-consuming).
• Needles and vascular access care.
• Possible side effects:

1. Low blood pressure during sessions
2. Muscle cramps
3. Tiredness after dialysis

• Lifestyle adjustments: diet control, fluid restrictions, and sticking to a routine.

Peritoneal Dialysis

Peritoneal dialysis is a method to clean your blood inside your body (as opposed to hemodialysis, which uses a machine). It utilises your abdominal lining (the peritoneum) to filter waste and excess fluid.

• First, a catheter (a soft tube) is placed into your belly by a surgeon, some weeks before starting dialysis.
• You use a special fluid (called dialysis solution) that flows through this catheter into your belly.
• That fluid sits there (dwell time), absorbing waste and fluid from your blood via the peritoneum.
• After a few hours, drain out the used fluid, discard it, and replace it with a fresh solution. This process is called an exchange.

Types Of Peritoneal Dialysis

There are two main kinds. You or your doctor can choose the one that best fits your lifestyle.

Continuous Ambulatory Peritoneal Dialysis (CAPD)

1. Performed by hand (no machine) during the day.
2. Usually involves 4-6 exchanges per day.
3. You keep the solution in your belly for several hours each time (this is called dwell time) and often have fluid in your belly even while you sleep.

Automated Peritoneal Dialysis (APD)

1. Uses a machine (sometimes called a cycler) that automatically fills and drains the fluid while you sleep.
2. In the morning, you wake up with fresh fluid in your belly. Sometimes,s may have an extra exchange during the day.

Where & How to Do It

• You can perform peritoneal dialysis at home, at work, or even while travelling, as long as you have a clean, private space.
• If you're travelling, the supplier can arrange for dialysis supplies to be sent to your location. However, for APD, you may need to carry a cycler or arrange for one, or perform manual exchanges if required.

Preparing for Peritoneal Dialysis

• A minor surgery is needed to place the catheter into the peritoneal cavity, usually below the belly button. It’s recommended to wait ~3 weeks after surgery, if possible, to allow the catheter to sit and heal properly.
• You’ll train with a nurse (1-2 weeks usually) to learn how to:

1. Do the exchanges (how to connect, drain fluid, refill)
2. Maintain a clean and sterile environment to prevent infection.s
3. Handle supplies (storage, handling, mask use, etc.).

Challenges

Using peritoneal dialysis means some day-to-day changes. Here are things to expect:

• Routine changes

1. You’ll have scheduled times for exchanges (manually or via machine).
2. May need to modify or delay certain physical activities when your belly is full of fluid.

• Diet and fluids

1. Limit salt (sodium), phosphorus, and fluids as advised by your dietitian.
2. You may need to increase your protein intake, as dialysis can remove some of it.

• Risks / Problems

1. Infection (especially around the catheter exit site or peritonitis in the abdominal fluid).
2. Hernias occur because placing fluid in the belly puts pressure on the abdominal muscles.
3. Possible weight gain from absorbing sugars (like dextrose) in the dialysis fluid.

How can you tell if it’s working?

• Monthly tests: doctors will check blood and also examine the used dialysis fluid to see if waste is being removed.
• If you still make urine, that helps too, and doctors may monitor it.
• If results aren’t good (e.g., wastes are still high, too much sugar absorbed, etc.), your doctor may adjust how many exchanges you do, dwell time, or which type (CAPD vs. APD).

Continuous Renal Replacement Therapy (CRRT)

CRRT is a type of dialysis used primarily in hospitals for critically ill patients, especially those in intensive care units. It’s designed to work slowly and continuously over 24 hours rather than in shorter pulses.

When to Prefer?

Here are some situations where doctors prefer CRRT:

• When a patient has acute kidney injury (AKI) and is very unstable (for example, low blood pressure), rapid fluid changes (as in regular hemodialysis) are risky.
• For controlling fluid overload (excessive fluid in the body), do it gradually when there are severe electrolyte disturbances (like high potassium) or acid-base problems that require steady correction.
• In situations with rapidly increasing waste products, or high “catabolic rate” (body breaking down fast) — e.g., in cases like rhabdomyolysis or tumour lysis.

Here’s how CRRT Works:

Some main features and how it differs from regular hemodialysis:

• Continuous Process: Runs 24 hours a day (or nearly so), allowing for gentler removal of waste and fluid.
• Three Main Modalities:

1. CVVH — Continuous Venovenous Hemofiltration (uses convection)
2. CVVHD — Continuous Venovenous Hemodialysis (uses diffusion)
3. CVVHDF — Continuous Venovenous Hemodiafiltration (combines both convection + diffusion)

• Access: Uses a dual-lumen catheter (a tube with two channels) placed in a large vein (such as the internal jugular or femoral vein).
• Flow Rates and Dosage:

1. Blood flows more slowly than in usual intermittent dialysis.
2. The “effluent” (fluid removed) dose is often in the range of 20-25 m/ k/ hour for AKI patients. Furthermore, it reveals no additional survival benefit, but rather an increased risk.
3. Net ultrafiltration (removing excess fluid) is carefully controlled.

• Anticoagulation: Because blood is outside the body in tubing/machine, there’s a chance of clotting. Therefore, anticoagulants (blood thinners), such as Heparin or citrate, are necessary.

Benefits of CRRT

• Much gentler on the body (especially for unstable patients) — less risk of sudden drops in blood pressure.
• Better fluid control over time (since removal is slow and steady).
• Can better manage the continuous buildup of waste in very ill patients.

Challenges of CRRT

• It usually requires ICU-level care, including continuous monitoring and adjustments.
• Higher risk of complications related to vascular access (infection, bleeding, catheter problems).
• Electrolyte imbalances (e.g., low phosphate, potassium), acid-base disturbances.
• Loss of specific nutrients/vitamins, etc., because of continuous filtration.
• Equipment is specialised; a trained team (nurses, nephrologists, pharmacists, and nutritionists) is needed.

>>Read More: Going For Dialysis Learn How To Choose Health Insurance To Manage Dialysis Cost

Final Words

Understanding the different types of dialysis helps you feel more prepared for your future consequences and keep your health journey under control. Hemodialysis, peritoneal dialysis, and CRRT each have their own processes, benefits, and challenges in critical care. Choosing the right option depends on your overall health, lifestyle, and your doctor's recommendations.

Dialysis isn’t just a treatment—it’s a lifeline for people whose kidneys can no longer perform their job. Since it often becomes a long-term part of life, it brings daily changes in daily routine, regular checkups, and ongoing expenses. That’s why having a reliable health insurance plan can ease the burden and give you the support you need along the way. Just as dialysis helps your body stay balanced, health coverage ensures your finances remain secure during treatment. Protecting your health and your peace of mind go hand-in-hand—and with the proper support, you can focus on living better, not just managing illness.

Disclaimer: All plan features, benefits, coverage, and claims underwriting are subject to policy terms and conditions. Kindly refer to the brochure, sales prospectus, and policy documents carefully.