What Is Kidney Dialysis and Why Is It Needed?

Dialysis is a medical treatment that performs the essential work your kidneys can no longer do on their own. The purpose of this treatment is to remove harmful waste products, excess fluid and toxins from the bloodstream, as well as to help balance the levels of minerals and electrolytes in your body.

Doctors typically recommend dialysis for individuals with chronic kidney disease that has progressed to kidney failure, or for those with acute kidney injury that requires temporary support.

Types of Kidney Dialysis

There are two main forms of dialysis: haemodialysis and peritoneal dialysis. Your doctor will recommend the most suitable option based on your lifestyle and medical needs.

Haemodialysis: This method uses a machine to filter the blood outside your body. During haemodialysis treatment, blood is drawn from your body through a vascular access point, passed through a dialyser (artificial kidney) that removes waste and excess fluid, and then returned to the bloodstream.
Peritoneal Dialysis: This technique uses the lining of the abdomen (peritoneum) as a natural filter. During peritoneal dialysis, a cleansing fluid called dialysate is introduced into the abdomen through a catheter. This fluid absorbs waste products and excess fluid from your blood vessels in the abdominal lining. After several hours, the fluid is drained and replaced with fresh dialysate.

What Happens During the Kidney Dialysis Process?

Kidney dialysis follows a structured process, designed to be safe and supportive. While the exact steps may vary depending on the type of dialysis you are undergoing, each session typically has a preparation phase, treatment phase and a period of monitoring afterwards.

Before Dialysis

Before your first dialysis session, your doctor will provide details about your chosen dialysis method, including dietary recommendations, fluid restrictions and what to expect during treatment. Your doctor will make an effort to answer any questions you have and ensure that you understand the process.

If you are starting haemodialysis, you will have to undergo a minor surgery to create a vascular access point. This is usually done several weeks before your first treatment to allow the access site to heal and mature.

Most haemodialysis patients attend a dialysis centre three times a week, with each session lasting 3–4 hours. Your first few sessions may take longer as the medical team adjusts settings specifically for you.

On the day of your session, the medical team will check your weight, blood pressure and general condition before treatment begins. This helps them determine how much fluid needs to be removed and ensures the dialysis settings are appropriate for you. You will then be comfortably seated or positioned while the nurses prepare the dialysis machine and access site. The environment is designed to help you remain relaxed and comfortable throughout the process.

During Dialysis

During haemodialysis, you will sit in a comfortable reclining chair while the dialysis machine does its work. Nurses will monitor your vital signs throughout the session, checking your blood pressure, heart rate and how you are feeling. Many patients read, watch television or sleep during treatment.

Once the session is complete, the dialysis machine is disconnected and the needles are carefully removed from the access site. The nurse will apply pressure to stop any bleeding and place a small dressing over the area before checking your blood pressure again to ensure you are stable.

With peritoneal dialysis, you will follow a specific schedule for filling and draining the dialysate solution from your abdomen through a catheter. Each exchange typically takes about 30–40 minutes. After the fluid has absorbed waste products, it is drained out and replaced with fresh solution. Most patients perform four to six exchanges daily according to their prescribed schedule.

After the exchange is complete, the catheter is securely capped and the area will be sterilised to reduce infection risk.

After Dialysis

After dialysis, the medical team will ensure you are stable before you leave. Your blood pressure and general condition may be checked again, and the access site will be monitored for any bleeding, swelling or signs of irritation. Patients are usually advised to rest briefly after the session and avoid heavy lifting or pressure on the access site for the rest of the day.

As your body adjusts to dialysis, you may experience some side effects, particularly during your first few sessions. These may include:

Mild fatigue or tiredness
Muscle cramps
Nausea or headaches
Dizziness or low blood pressure
Mild discomfort at the access site

These symptoms usually improve with time. However, if they persist or worsen, inform your doctor immediately, so they can adjust your treatment to help you feel more comfortable.

Living Well With Dialysis

Adjusting to dialysis takes time, but most patients find that they feel better than they have in months or even years. To get the most from your treatment, it is important to:

Attend all scheduled dialysis sessions
Take your prescribed medications
Follow your recommended diet and fluid restrictions
Stay as active as possible
Communicate openly with your healthcare team

With the right care and support, many individuals on dialysis continue to lead fulfilling, active lives while managing kidney health effectively.

If you have concerns about your kidney health or need guidance on dialysis treatment options, The Kidney Health Care Clinic offers comprehensive, personalised care to support you on your journey. Led by our medical director and senior consultant nephrologist, Dr Alvin Ng Kok Heong, we provide thorough kidney evaluations, dialysis planning and long-term management for chronic kidney disease. Dr Ng’s practice focuses on delivering patient-centred care, helping individuals understand their condition and choose the most appropriate treatment options for their needs.

Contact us to schedule a consultation with our kidney doctor and learn more about how to manage your renal health with confidence.

Meet Our Kidney Specialist in Singapore

Dr Alvin Ng Kok Heong
Senior Consultant Nephrologist
MBChB (Auckland), FRACP (Aus), FAMS (Renal Medicine)

Dr Alvin Ng is a nephrologist and kidney specialist in Singapore with more than 20 years of experience. He specialises in managing a wide range of kidney conditions and is dedicated to providing comprehensive, personalised and evidence-based care for patients with kidney disease.

Dr Ng obtained his Bachelor of Medicine and Surgery from the University of Auckland in 2002 and completed his nephrology training in New Zealand. He was admitted as a Fellow of the Royal Australasian College of Physicians in 2010. Prior to private practice, he served as a Consultant Nephrologist at North Shore Hospital, Auckland, from 2010 before joining the Department of Renal Medicine at Changi General Hospital (CGH) in 2012.

Throughout his career in public healthcare, Dr Alvin Ng held several leadership positions within the nephrology community and received numerous awards in recognition of his service and dedication as a kidney specialist.