The kidneys perform several essential functions every day. They remove waste products from the blood, regulate fluid levels, maintain electrolyte balance and help control several processes that are important for overall health.

When the kidneys become severely impaired, they may no longer be able to perform these functions adequately. Dialysis is a treatment that replaces some of the kidneys' filtering functions.

The main function of dialysis is to remove waste products and excess fluid from the blood while helping maintain appropriate levels of certain electrolytes and acid-base balance.

Dialysis does not completely replace every function of healthy kidneys, and it does not automatically cure the underlying kidney disease.

At Prabhakar Bhurke Clinic, Dr. Sandip Prabhakar Bhurke, super specialist nephrologist and transplant physician, provides specialized care for patients with kidney disease, advanced kidney failure and dialysis-related medical conditions.

Why Is Dialysis Needed?

Healthy kidneys continuously filter the blood. When kidney function becomes severely reduced, substances that would normally be removed through urine can accumulate in the body.

This may result in:

• Waste-product accumulation

• Fluid overload

• High potassium levels

• Acid-base disturbances

• Swelling

• Breathlessness

• Nausea

• Loss of appetite

• Severe fatigue

• Other complications of advanced kidney failure

Dialysis can help manage some of these problems when the kidneys cannot adequately do so themselves.

Main Functions of Dialysis

1. Removes Waste Products

One of the most important functions of dialysis is removing waste products that accumulate when kidney filtration becomes severely impaired.

These substances include urea and other metabolic waste products.

During dialysis, waste moves from the blood into a dialysis solution across a membrane or filter and is subsequently removed from the body.

2. Removes Excess Fluid

When kidney function is severely reduced, the body may retain more water and salt than it can eliminate.

Excess fluid can cause:

• Swelling of the legs or face

• Increased blood pressure

• Breathlessness

• Fluid accumulation around or inside organs

Dialysis can remove a controlled amount of excess fluid.

The amount removed during a dialysis session is individualized according to the patient's condition, weight changes, blood pressure and fluid status.

3. Helps Control Electrolytes

Kidneys help maintain appropriate concentrations of electrolytes in the blood.

When kidney function declines, electrolytes such as potassium may rise to dangerous levels.

Dialysis can remove excess potassium and help correct certain electrolyte disturbances.

Other electrolytes, including sodium and calcium, may also be affected by kidney failure and its treatment.

4. Helps Correct Acid-Base Imbalance

Healthy kidneys help maintain the body's acid-base balance.

Advanced kidney disease can cause acid to accumulate, resulting in metabolic acidosis.

Dialysis can help remove certain acids and restore part of the body's acid-base balance.

5. Reduces Symptoms of Uremia

When kidney function becomes severely impaired, waste products can accumulate and produce a condition known as uremia.

Possible symptoms include:

• Nausea

• Vomiting

• Loss of appetite

• Fatigue

• Itching

• Difficulty concentrating

• Confusion

• Sleep disturbances

Dialysis can reduce the concentration of certain waste products and may improve symptoms related to uremia.

How Does Hemodialysis Work?

Hemodialysis uses a dialysis machine and a special filter called a dialyzer.

A typical treatment involves several steps.

Step 1: Blood Access

Blood is removed from the body through a vascular access.

Common forms include:

• Arteriovenous fistula

• Arteriovenous graft

• Central venous catheter

Step 2: Blood Enters the Dialyzer

The patient's blood travels through the dialyzer.

Inside the dialyzer are numerous tiny fibers that allow waste products and excess substances to move across a specialized membrane.

Step 3: Waste and Fluid Are Removed

Dialysis fluid, called dialysate, flows on the other side of the membrane.

Differences in concentration allow certain waste products and electrolytes to move from the blood into the dialysate.

Fluid can also be removed through a process called ultrafiltration.

Step 4: Filtered Blood Returns

The cleaned blood is returned to the patient's bloodstream.

The entire process is monitored by the dialysis machine and healthcare team.

How Does Peritoneal Dialysis Work?

Peritoneal dialysis uses the patient's own abdominal lining, called the peritoneum, as a natural filtering membrane.

A dialysis solution is introduced into the abdomen through a catheter.

Waste products and excess fluid move from the blood across the peritoneal membrane into the dialysis solution.

The used solution is then drained and replaced with fresh solution.

Peritoneal dialysis can be performed through different schedules and methods depending on the patient's treatment plan.

Dialysis vs Healthy Kidney Function

Dialysis performs several important functions of the kidneys, but it is not identical to having healthy kidneys.

Healthy kidneys work continuously and perform many functions, including:

• Filtering blood continuously

• Producing urine

• Regulating fluid balance

• Managing electrolytes

• Helping control acid-base balance

• Supporting blood pressure regulation

• Producing erythropoietin

• Activating vitamin D

• Performing other endocrine and metabolic functions

Dialysis mainly replaces selected filtration and fluid/electrolyte functions.

This is one reason patients with advanced kidney failure may still require additional medicines and medical management even when receiving regular dialysis.

Does Dialysis Cure Kidney Failure?

Dialysis is generally a treatment, not a cure for irreversible chronic kidney failure.

It replaces some kidney functions while the treatment is being provided.

For patients with permanent kidney failure, dialysis may be required long term unless kidney transplantation or another suitable treatment option becomes available.

However, dialysis can sometimes be temporary in acute kidney injury.

If kidney function recovers sufficiently after the underlying problem is treated, dialysis may no longer be necessary.

When Is Dialysis Started?

The decision to start dialysis is not based on a single creatinine value.

A nephrologist considers the overall clinical picture, including:

• Kidney function

• Symptoms

• Fluid overload

• Potassium levels

• Acid-base disturbances

• Uremic complications

• Nutritional status

• Response to medical treatment

• Overall health

In some situations, dialysis may be required urgently.

In other patients with advanced CKD, treatment can continue without dialysis while kidney function and symptoms are carefully monitored.

What Happens During a Dialysis Session?

During hemodialysis, the patient is connected to the dialysis machine through vascular access.

The healthcare team monitors:

• Blood pressure

• Heart rate

• Weight

• Fluid removal

• Dialysis settings

• Symptoms during treatment

The exact duration and frequency of dialysis vary according to the patient's needs.

Some people receive dialysis several times a week, while treatment schedules can differ depending on the type of dialysis and individual circumstances.

What Are the Benefits of Dialysis?

When appropriately prescribed, dialysis can:

• Remove accumulated waste

• Reduce excess fluid

• Help control potassium

• Help correct acid-base disturbances

• Improve symptoms related to uremia

• Support patients whose kidneys cannot adequately maintain internal balance

• Provide life-sustaining kidney replacement therapy in advanced kidney failure

The benefits depend on the patient's medical condition and how well the treatment addresses their specific problems.

Are There Side Effects of Dialysis?

Dialysis can cause complications or treatment-related symptoms.

During or after hemodialysis, some patients may experience:

• Low blood pressure

• Muscle cramps

• Fatigue

• Headache

• Nausea

• Dizziness

Long-term dialysis can also involve complications related to vascular access, infection, cardiovascular health and other medical conditions.

Not every patient experiences these problems.

Regular monitoring helps the medical team identify and manage complications.

Why Is Fluid Management Important During Dialysis?

Fluid management is one of the important functions of dialysis.

When someone produces little urine, drinking more fluid than the body can eliminate may result in fluid accumulation.

Excess fluid can contribute to:

• High blood pressure

• Swelling

• Breathlessness

• Heart strain

The dialysis team determines an appropriate fluid removal target based on the patient's clinical status.

Patients should follow the fluid recommendations provided by their nephrologist rather than using a fixed fluid target from an online article.

What Is the Role of Diet During Dialysis?

Dialysis patients often require individualized dietary guidance.

Depending on laboratory results and the type of dialysis, recommendations may involve:

• Sodium

• Potassium

• Phosphorus

• Protein

• Fluid intake

Nutritional requirements can differ between people receiving hemodialysis and those receiving peritoneal dialysis.

A renal dietitian or nephrologist can provide recommendations based on the patient's blood tests and treatment plan.

Can Dialysis Remove All Toxins From the Body?

No.

Dialysis removes many waste products and substances that can accumulate because of reduced kidney function, but it does not duplicate every function of healthy kidneys.

Some substances are removed more efficiently than others, depending on their size, concentration and characteristics.

This is why appropriate medication, nutrition, fluid management and regular medical follow-up remain important.

Dialysis and Kidney Transplantation

For eligible patients with irreversible kidney failure, a kidney transplant may be an alternative form of kidney replacement therapy.

A successful transplant can provide continuous kidney function from a donor kidney.

However, transplantation requires detailed medical evaluation and lifelong follow-up.

Some patients receive dialysis while waiting for transplantation, while others may undergo transplantation before starting long-term dialysis in selected circumstances.

Dialysis Care at Prabhakar Bhurke Clinic

At Prabhakar Bhurke Clinic, Dr. Sandip Prabhakar Bhurke provides super specialist nephrology and transplant-related care for patients with kidney disorders.

Depending on the patient's condition, care may involve:

• Evaluation of reduced kidney function

• Assessment of advanced kidney failure

• Dialysis-related medical management

• Fluid and electrolyte management

• Blood pressure management

• Complication monitoring

• Pre-transplant evaluation

• Post-transplant nephrology care

Treatment decisions are individualized according to kidney function, symptoms, laboratory results and overall medical condition.

Frequently Asked Questions

What is the main function of dialysis?

The main function of dialysis is to replace some of the kidneys' filtering functions by removing waste products and excess fluid and helping regulate certain electrolytes and acid-base balance.

Does dialysis remove creatinine?

Yes. Hemodialysis removes creatinine and other waste products from the blood. However, creatinine will generally accumulate again between treatments when kidney function remains severely reduced.

Does dialysis remove excess water?

Yes. Excess fluid can be removed during dialysis through ultrafiltration. The amount removed is carefully determined for each patient.

Can dialysis replace normal kidney function completely?

No. Dialysis replaces some important kidney functions but does not reproduce all the continuous hormonal, metabolic and regulatory functions of healthy kidneys.

Can dialysis be temporary?

Yes. In some patients with acute kidney injury, dialysis may be temporary if kidney function recovers sufficiently after the underlying cause is treated.

Does dialysis mean the kidneys have completely stopped working?

Not necessarily. Some patients receiving dialysis still have residual kidney function and may continue to produce urine. The amount of remaining function varies between individuals.

Conclusion

The function of dialysis is to provide essential kidney replacement support when the kidneys cannot adequately remove waste, control fluid levels or maintain certain electrolyte and acid-base balances.

Hemodialysis and peritoneal dialysis use different methods to achieve these goals, but neither completely reproduces every function of healthy kidneys.

For some people with acute kidney injury, dialysis may be temporary. For those with irreversible advanced kidney failure, dialysis can be a long-term treatment, while kidney transplantation may be an option for medically suitable patients.

If you or a family member has been advised to start dialysis, understanding why it is needed and what it does can make treatment decisions easier to discuss with your nephrologist.

For specialized nephrology and dialysis-related care, consult Dr. Sandip Prabhakar Bhurke at Prabhakar Bhurke Clinic.

Medical Disclaimer

This article is intended for general educational purposes only and does not constitute medical advice, diagnosis or treatment. The need for dialysis, type of dialysis, treatment frequency and fluid removal targets must be determined by a qualified nephrologist based on the patient's kidney function, symptoms, laboratory findings and overall health. Do not delay dialysis, change dialysis schedules, alter fluid intake or discontinue prescribed medicines based on information from this article. Seek urgent medical attention for severe breathlessness, chest pain, confusion, very little or no urine, severe weakness or sudden deterioration in health. Consult Dr. Sandip Prabhakar Bhurke or another qualified nephrologist for individualized medical care.