Dialysis Definition, Procedure, Types, Principle and Side Effects (original) (raw)
Last Updated : 21 Aug, 2025
**Dialysis is an **artificial procedure to remove excess wastes and fluids from the blood when a patient's kidneys are not functioning properly and naturally. Dialysis is also known as renal dialysis or kidney dialysis. The process helps **reduce the level of urea in the human blood **without affecting its glucose level.
In this article, we will **discuss the dialysis definition, principles, dialysis procedures, types, and advantages of Dialysis in detail.
Table of Content
- What is Dialysis?
- Principle of Dialysis
- Dialysis - Mechanism
- Dialysis - Diagram
- Symptoms for Dialysis Treatment
- Types of Dialysis
- Advantages of Dialysis
- Dialysis Side Effects
- Conclusion - Dialysis
- FAQs - Dialysis
What is Dialysis?
**Dialysis Definition - Dialysis is a treatment that filters the blood through an artificial dialyzer. The process works like our kidney but outside of our body. Dialysis removes the waste products and excess fluid from the bloodstream due to kidney failure.
Dialysis process **separates the smaller waste molecules from the larger molecules like red **blood cells. Dialysis is needed when a person suffers from kidney disorder or renal failure. The word dialysis evolved from an Ancient Greek word diálusis. In 1943 a young Dutch physician, **Dr. Willem Kolff developed the the first dialyzer, or an artificial kidney. He is considered as the father of dialysis.
**Also Read: Kidney - Introduction, Structure, Anatomy, Functions
Principle of Dialysis
**There are three major principles on which the process of dialysis works. Dialysis is a mechanical process that removes nitrogenous waste and extra water from the blood. It is an artificial process that takes place outside of a patient's body, similar to the kidneys' function in our body.
**Dialysate is also known as dialysis fluid or dialysis solution. It is a solution that removes toxic elements from the blood. It is a solution of pure water, electrolytes, and salts with some glucose or dextrose. It is the major component of the dialysis process.
Let us discuss the principles of the dialysis process:
Diffusion
The diffusion process takes place when the particles move from high concentration to less concentration areas. The impure blood moves towards the dialysate. The amount of waste removed in this process depends on the waste size. This is the process, of how diffusion works.
Osmosis
In the process of osmosis, the liquid goes from high water concentration to lower water concentration through a semi-permeable membrane. The same process sustains until the fluid level becomes the same between blood and dialysate. Dialysis removes extra fluid from the blood. The process took place under pressure to overcome a colligative property and osmotic pressure.
Ultrafiltration
Ultrafiltration is a convective flow of water that carries the tiny particles away due to pressure differences. In dialysis, this process helps to take out the waste material and extra fluids from the blood using a semi-permeable membrane. It's like a filtering process for fluids through a semi-permeable membrane.
**Dialysis - Mechanism
Dialysis is an artificial process that filters the patient's blood to prevent chemicals including potassium, bicarbonate, and sodium from reaching hazardous levels in the human body. The human kidney can filter around 100-150 quarts of blood per day. Dialysis treatment happens when kidneys are not functioning properly and the waste materials start accumulating in the blood which results in coma or ultimate death. The dialysis procedure flowchart is given below:
Start Dialysis
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Insert Needle for Blood Access
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Pass Arterial Blood Through Dialyzer by using some Anticoagulant
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Blood Moves Through Hemofilter in Dialyser
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Dialysate Bathes Outer Surface of Membranes
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Constantly Replaced with Fresh Dialysate
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Unwanted Substances Pass from Blood to Dialysate
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Essential Substances Diffuse from Dialysate to Blood
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Exchange of Substances Between Blood and Dialysate
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Blood Pumps and Pressure Monitors for Smooth Flow Between Patient and Machine
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Pumps for Fresh Dialysate Flow and Used Dialysate Drainage
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End of Dialysis
Dialysis - Diagram
Here is the pictorial representation of dialysis:
Symptoms for Dialysis Treatment
There are some symptoms that may indicate need of dialysis. They are:
- A sudden and/or persistent change in urination
- A metallic taste in the mouth, known as ammonia breath
- Itching
- Nausea
- Loss of appetite
- Swelling
- Fatigue
- Aversion from protein
Types of Dialysis
Dialysis is a mechanical process that removes nitrogenous waste and extra water from the blood. There are three different types of dialysis as mentioned below.
**Intermittent Hemodialysis (IHD)
In Intermittent hemodialysis (IHD) method, the patient’s blood is passed through the dialysis machine. In the dialysis machine the blood is purified and returned to the patient’s body through an another channel. Like our kidneys, the filters remove the waste materials from the blood but as an artificial kidney. There are some preparation needed for those who are going to have intermittent hemodialysis (IHD). They need to enlarge the arm blood vessel. It helps to insert the catheters into the patient’s body.
**Peritoneal Dialysis (PD)
Peritoneal dialysis (PD) is a surgical implantation where a catheter needs to enter to the stomach of the patient. After that, the dialysate circulated throughout the catheter. It absorbs the waste materials from the blood vessels which are present in the walls of the patient’s stomach. Peritoneal dialysis is considered as a versatile and convenient process than the intermittent hemodialysis (IHD). The process can be done for several times during the day. It can be done overnight with an automated system as well. Overall it takes time up to 6 hours.
Advantages of Dialysis
There are so many advantages of dialysis. Let us discuss:
- Dialysis can be carried out at home also.
- It maintains the fluid balance of the human body by removing excess fluid.
- Peritoneal dialysis is a comfortable process that is easy to use.
- The equipment used in peritoneal dialysis is easy to carry with the patient.
- The process removes waste products like urea and creatinine and controls the blood pressure.
- It balances the pH levels in the blood and removes the symptoms of fatigue and nausea.
- Overall, it extends the lifespan of patients with kidney failure.
**Read More: Blood -[ Components, Functions, Groups and Disorders](https://Blood - Components, Functions, Groups and Disorders)
Dialysis Side Effects
Though Intermittent hemodialysis (IHD), Peritoneal dialysis (PD) have their advantages, there are some side effects of dialysis too. They are:
- Dialysis may cause fatigue. It makes you feel tired and exhausted all the time. It is a common side effect of the process.
- Low blood pressure is also a common side effect and it may cause a drop the fluid levels during dialysis with nausea and dizziness.
- Blood poisoning or Sepsis may risk your body and internal organs due to having continuous dialysis.
- Some people experience muscle cramps during dialysis, generally in the lower leg.
- Itchy skin is another side effect that can be caused by the build-up of minerals in the human body.
Conclusion - Dialysis
Dialysis can be a temporarily way to carryout the same function as kidneys do. But it is a true fact it can not replace our kidneys completely. The process of dialysis is a mechanical process that purify the patient's blood outside their body. Dialysis is needed due to kidney failure. The process helps to reduce the level of urea in the human blood without affecting its glucose level. The human kidney can filter around 100-150 quarts of blood per day. When kidneys are not functioning properly the waste materials start accumulating in the blood which results in coma or ultimate death.
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