What to Expect During Your Haemodialysis Procedure: A Complete Guide

Starting dialysis can raise many practical questions. What do you find when you arrive? How does the machine purify your blood? What can you expect to feel throughout treatment? Knowing what to expect can make the first few sessions simpler to follow.

In haemodialysis, a dialysis machine and a filter called a dialyser remove waste materials and excess fluid from the blood. Understanding what happens to your body during dialysis will help you prepare for treatment and give you a clearer picture of the process.

Preparing for Your First Dialysis Session: What to Expect

Before your first haemodialysis treatment, your care team will explain the treatment, evaluate your vascular access and review your prescribed schedule. For haemodialysis, you need a safe way for blood to leave your body, pass through the dialysis machine and return after it is cleaned. This can be done through a fistula, graft or catheter. For the first session, it can be helpful to:

• Wear comfortable clothing that allows for straightforward access for dialysis.
• Bring medicines and relevant medical information if asked for.
• Follow directions regarding diet, water and medication before treatment.
• Inform the team of any symptoms or changes in your health.

Most people treated in a centre go about three times a week for around four hours, although treatment times vary according to the individual’s needs.

Step 1: Pre-Treatment Arrival & Vital Checks

When you arrive, the dialysis staff will assess your weight and vital indicators, including blood pressure and pulse. Knowing your weight before treatment helps the team predict how much excess fluid they need to drain. The dialysis staff also check for signs of infection or other issues at the access site. These checks help the team assess if your prescribed treatment is appropriate for that day.

Step 2: Connecting to the Haemodialysis Machine

When you are ready, the nurse or technician attaches your vascular access to the dialysis machine. With a fistula or graft, the procedure normally involves two needles. One line takes blood from your body to the machine and the other returns filtered blood.

In haemodialysis, the machine controls blood flow and monitors pressure. Only a small amount of blood is outside your body at any instant as it flows through the tubing and dialyser before returning to you.

Step 3: The Blood Filtration Process Inside the Dialyser

The dialyser is commonly called an artificial kidney. Blood passes through very fine hollow fibres in it and dialysis fluid flows in the opposite direction on the other side of the membrane.

It becomes easier to understand what happens to the body during dialysis when you think of the process as continuous circulation. The filtered blood is returned to the body and the dialysis solution takes away the waste products and excess minerals.

Haemodialysis can remove compounds like urea and creatinine, as well as excess salt and water. The dialysis solution is tailored to the patient’s needs and can be modified as necessary.

Step 4: Fluid Removal Through Ultrafiltration

A major part of treatment is removing excess fluid. If kidney function becomes very poor, the body can retain fluid between dialysis sessions. This might cause oedema, high blood pressure or breathing problems.

During ultrafiltration, the dialysis machine removes a set amount of fluid based on your weight, desired or dry weight, blood pressure and clinical condition because removing liquids too fast can induce dizziness, weakness, nausea or muscular cramps. That is why the rate of fluid loss is evaluated during treatment.

Step 5: What Happens During the 3-4 Hour Session?

A typical in-centre session lasts around four hours, although some people require shorter or longer treatment. Nurses or technicians monitor your blood pressure while you sit or recline.

Understanding what happens to your body during dialysis can also help you recognise why you may feel different during treatment. Some people experience tiredness, headaches, dizziness or muscle cramps. Tell the dialysis team promptly if you feel unwell because the treatment settings or fluid removal rate may need adjustment.

Step 6: Completing the Treatment & Disconnection

When the prescribed treatment time is complete, the machine returns the blood remaining in the circuit to your body. The needles are removed if you have a fistula or graft and pressure is applied to the sites until bleeding stops. A catheter is disconnected and dressed according to the care team's protocol.

At the end of a haemodialysis procedure, your weight and vital signs may be checked again. This helps the team assess how much fluid was removed and plan future sessions.

Knowing what to expect after haemodialysis can help you understand how you feel after each session. Some people feel fatigued, while others feel well. If you experience persistent dizziness, severe weakness, chest discomfort or breathlessness, inform your care team promptly.

Conclusion

A haemodialysis procedure follows a structured process, from the initial weight and vital checks to blood filtration, fluid removal and final disconnection. When you know what happens at each stage, the treatment becomes more predictable and allows you to communicate effectively with your dialysis team.

For patients and families, knowing what to expect after haemodialysis can make ongoing care easier to plan. NephroPlus provides several dialysis options, including in-clinic dialysis, home haemodialysis, dialysis on wheels, dialysis on call and holiday dialysis. The appropriate option depends on medical requirements, treatment prescription and individual circumstances.

Frequently Asked Questions (FAQ's)

Does haemodialysis hurt?

The dialysis process itself is not usually painful. Needle insertion can cause brief discomfort when a fistula or graft is used. Tell the dialysis team if you experience significant pain or discomfort during treatment.

How long does a typical haemodialysis session last?

A typical in-centre haemodialysis session lasts about three to four hours, with many sessions lasting around four hours. The exact duration depends on your kidney function, treatment needs and dialysis prescription.

Can I eat or drink while on the haemodialysis machine?

The answer depends on your dialysis centre and individual dietary and fluid plan. Some centres allow food during treatment, but fluid intake may need to be limited. Ask your dialysis team what is appropriate for you.

How much blood is outside my body during haemodialysis at any given time?

Only a small amount of blood is outside your body at any given time. It continuously flows through the dialysis tubing and dialyser before returning to your bloodstream. The exact amount varies depending on the dialysis machine and tubing system.

What should I do if I feel dizzy or get muscle cramps during dialysis?

Tell the dialysis nurse or technician immediately. Dizziness and cramps can occur when blood pressure falls or fluid is removed too quickly. The team can assess you and adjust the treatment if necessary. This is part of what to expect after haemodialysis. Understanding what happens to the body during dialysis does not mean you should ignore symptoms during treatment.