Haemodialysis Dialysis

Tyneside Kidney Patients Association

How does haemodialysis work?

Blood taken from the body to be cleaned in a filter known as a dialyser (artificial kidney). A dialyser works on the principle of blood flowing along one side of a semi-permeable membrane made of cellulose or a similar product, with the dialysate flowing along the other side. The dialysate contains a regulated amount of minerals normally present in the blood, but in renal failure they are present in excess. The membrane has tiny holes of different sizes so that the excess fluid and substances in the blood pass through at different rates, small molecules quickly and larger ones more slowly, to be taken away in the dialysate until a correct balance in the blood is achieved.

A kidney machine regulates blood flow, pressure and the rate of exchange.

As only a very small amount of blood is in the dialyser at any given time, blood needs to circulate from patient to dialyser to patient for about 4 hours. Treatment is usually 3 times per week. The time and strength of dialysis can be programmed for each patient.

Blood is carried from the patient to the dialyser and returned through dialysis lines (plastic tubes) which are connected to the patient in one of two ways:


The joining of a vein and artery just under the skin, usually on the forearm makes the vein swell to allow needles to be inserted and removed after each treatment. Between treatments only a small scar and swelling are visible.

Central Venous catheter

A soft plastic tube inserted in a large vein, either in the side of the neck or, less often, into the top of the leg. This is capped off when not in use. For more information click here.

Where will I have my treatment?

Some patients dialyse in hospital; others have the equipment installed at home. This will depend on what facilities your hospital can offer, on medical criteria and on your own preference. A satellite or minimum care unit may be near your home. Such units are suitable for patients who are in good general health, not needing the services and care of a main renal unit.

Initial treatment and training is given at a renal unit usually found only in larger hospitals. You may then prefer the flexibility of home dialysis but there are disadvantages. You will need help with the treatment and taking all the responsibility for dialysis can be stressful for both patient and carer.

If you have no room for a kidney machine, have no carer or need medical supervision, hospital dialysis is a better option. Your home is free of the equipment but you will have to fit your life around the renal unit’s regime and travelling is time consuming.

Patients have different needs and you should discuss with your doctor which system best suits your lifestyle.

Will dialysis cure my kidney failure?

Dialysis takes over the role of the kidneys. It will not cure your kidney failure. The alternatives to dialysis are death from kidney failure, or a kidney transplant. For some people whose kidneys have failed after an operation or a bad infection, kidney failure will only be temporary and the kidneys will recover in time. For most people, though, the kidneys will not recover and the need for dialysis will continue.

Will dialysis keep me well?

There is no real substitutes for your own healthy kidneys and we cannot promise that you will feel as fit as you did before kidney failure. To keep as well as possible your treatment will consist of the 3 Ds - dialysis, diet and drugs. The haemodialysis diet is quite strict, limiting your intake of fluid and foods which are high in salt, potassium and protein. This is not as bad as it sounds and imaginative cooking can produce nourishing and tasty meals. Eating out is possible with a little care.

Commonly prescribed drugs are calcium carbonate and aluminium hydroxide to prevent a build-up phosphate which combines with calcium to damage the blood vessels. Resonium is taken if there is a danger of high blood potassium level as this is a life threatening condition. Some patients need vitamin and iron tablets and medication for high blood pressure. Erythropoetin (EPO) is very helpful in treating renal anaemia.

There will be times when you will feel very tired – it’s the same with most chronic illnesses. Stick to the advice you are given and you should be well enough to do most normal activities, even if you do need to pace yourself carefully.

I’m not sure I can cope – Who can I talk to?

In addition to the doctors and nurses you will meet, most renal units have a dietician, social worker, psychologist and home sister. Thousands of patients have successfully passed through difficult early stages of renal failure and there’s nothing quite like talking to someone who’s ‘been there’. The National Kidney Federation can put you in touch with your local Kidney Patients Association.

Will I be able to continue with my job or studies?

In most cases, yes. A heavy job may be difficult, some people on dialysis do have the strength for this, others are restricted to lighter work. Some people adjust their working hours; others fit dialysis into evenings and weekends.

Can I claim Social Security benefits?

HD patients might be entitled to Personal Independence Payments or Employment Support Allowance. You may get more information from a Renal Social Worker or Citizen’s Advice Bureau. You can also request the NKF Know Your Benefits pack by ringing the NKF Helpline on (0845) 601 02 09.

Will I be able to go on holiday?

Yes. Arrangements can be made to dialyse at other units at home and abroad – provided they can fit you in. Most Kidney Patients Associations have holiday facilities or organise group holidays.

Is dialysis treatment painful?

Once you get the knack of inserting needles, dialysis is not painful but it can be uncomfortable. Your biochemical levels rise between treatments and drop rapidly during dialysis. This may cause you to feel faint, generally unwell, have a headache or feel ‘washed out’ after treatment. These feelings should pass quickly and some patients are not affected at all. If symptoms persist you should tell your doctor as you may need an adjustment to your dialysis regime.

Are there any complications?

Common complaints are anaemia, cramp, skin irritation, weight loss and uraemia (excess of waste products in the blood). Long term problems may include depression, diminished sexual function, abnormal bone regeneration and bone pain.

Most patients experience some of these complications ... but that does not mean you’re bound to get all of them! Patients have reported that many of the symptoms of renal failure – itching, lethargy, mood fluctuations, interference with sleep patterns and sexual function - have been much improved by taking the drug erythropoetin (EPO).

Will I need dialysis for the rest of my life?

As long as you have no renal function you will need some form of dialysis. Many patients can look forward to having a kidney transplant. Unfortunately, some are medically unsuitable. Your doctor will advise you on this, however. If you have a successful transplant then dialysis treatment will cease – no dialysis, means there's no need for a renal diet – but you will still have to take certain drugs.