Ideally, a kidney transplant should be performed when tests show that the extent of damage to your kidneys is so great that you'll need dialysis within the next 6 months.

However, because of the lack of available kidneys, it's unlikely you'll receive a kidney donation at this time, unless a family member or friend who has a similar tissue type is willing to make a living donation.

Most people with kidney failure need dialysis while they wait for a donated kidney to become available.

The average time a person spends on the waiting list for a kidney transplant is 2 and a half to 3 years, although it can be shorter or longer than this.

How donations are allocated

Demand for donations from recently deceased people far outstrips supply, so there are strict but necessary guidelines about how donations are allocated.

Children and young adults are generally given priority if a matched donation becomes available, as they'll most likely gain a longer-term benefit from a transplant.

For older adults, a scoring system is used to determine who should get a donation. The score is based on factors such as how long you've been on the waiting list and how well matched the donor is in terms of tissue type, blood group and age.

Waiting for a transplant

If you're on the waiting list for a kidney, the transplant centre will need to contact you at short notice once a kidney becomes available, so you must inform staff if there are any changes to your contact details.

You should also inform staff if there are changes to your health – for example, if you develop an infection.

While waiting for a donated kidney to become available, it's important to stay as healthy as possible by:

• eating a healthy diet – read more about healthy eating
• taking regular exercise if possible – read more about exercise and getting fit
• cutting down on alcohol – recommended limits for alcohol consumption are 14 units a week for men and women; read some tips on cutting down on alcohol
• stopping smoking if you smoke – read more about stopping smoking

Make sure you always have an overnight bag ready for when the call comes, and make arrangements with friends, family and work so you can go to the transplant centre as soon as a donor kidney becomes available.

Transplant centres

In England, there are 20 NHS specialist kidney transplant centres; 6 in London, and the rest in the following 14 cities:

• Birmingham
• Bristol
• Cambridge
• Coventry
• Leeds
• Leicester
• Liverpool
• Manchester
• Newcastle
• Nottingham
• Oxford
• Plymouth
• Portsmouth
• Sheffield

Read more about kidney transplant units on the NHS Blood and Transplant website.

When a suitable donor kidney is found, the transplant centre will contact you. Staff at the centre will check you don't have any new medical problems and then ask you to go to the centre.

When you hear from the transplant centre:

• don't eat or drink anything
• take all current medicines with you
• take a bag of clothes and essential items for your hospital stay

When you arrive at the transplant centre, you'll be quickly assessed. Some of the tests you had at your initial assessment may be repeated to ensure no new medical conditions have developed. Tests will also be done to ensure the donor kidney is suitable for you.

The transplant procedure must be carried out as quickly as possible for the transplant to have the best chance of success. After the medical team has confirmed the kidney is in good condition and is suitable, you'll be given the general anaesthetic and taken to the operating theatre.

The operation

The kidney transplant procedure involves 3 main stages:

• First, an incision (cut) is made in your lower abdomen (tummy), through which the donated kidney is put into place. Your own kidneys will usually be left where they are, unless they're causing problems such as pain or infection.
• Second, nearby blood vessels are attached to the blood vessels of the donated kidney. This is to provide the donated kidney with the blood supply it needs to function properly.
• Finally, the ureter (the tube that carries urine from the kidney to the bladder) of the donated kidney is connected to your bladder.

A small plastic tube called a stent may be inserted into the ureter to help ensure a good flow of urine initially. This will usually be removed about 6 to 12 weeks later during a minor procedure called a cystoscopy.

When the kidney is properly in place, the incision in your abdomen will be closed with surgical staples, stitches or surgical glue.

Although the procedure may sound relatively straightforward, it's very demanding and complex surgery that usually takes around 3 hours to complete.

After the operation

Once you've recovered from the effects of the anaesthetic, it's likely you will feel some pain at the site of the incision. Painkillers will be provided, if necessary.

After the operation, you'll immediately begin treatment with medication designed to prevent your immune system from rejecting your new kidney. See living with a kidney transplant for more information on this.

Most transplanted kidneys will start working immediately, particularly if they come from a living donor, although sometimes they may take a few days or weeks to work properly. If this is the case, you'll need to have dialysis during this time.

Most people can leave hospital in about a week, but you'll need to attend frequent appointments at the transplant centre, so your kidney function can be assessed and tests can be carried out to check how well your medications are working.

For the first month after surgery, you may need to have 2 to 3 appointments a week. However, over time, your appointments will become less frequent. After a year, as long as you do not have any serious problems, you should only have to attend the centre once every 3 to 6 months.

After kidney surgery, you should be able to return to work and normal activities within a few months, provided you make good progress.

The following lifestyle advice is usually recommended to help you stay healthy after a kidney transplant.

Stop smoking

If you smoke, it's strongly recommended that you stop as soon as possible because smoking can reduce the life of your new kidney and can increase your risk of developing some types of cancer.

The NHS Smokefree website can provide support and advice to help you stop, and your GP can also recommend and prescribe treatments that can help. Read more about stopping smoking.

Diet

Most people are able to enjoy a much more varied diet after a kidney transplant, although you may be advised to avoid some foods after the operation until the kidney is working properly.

During the early stages after a transplant, while you're on higher doses of immunosuppressant medication (see below), you should avoid eating foods that carry a high risk of food poisoning, including:

• unpasteurised cheese, milk or yoghurt
• foods containing raw eggs (such as mayonnaise)
• undercooked or raw meats, fish and shellfish

Once your kidney is working properly and the best immunosuppressant dose for you has been identified, you'll usually be advised to follow a generally healthy diet, as this can reduce your risk of complications such as diabetes. 

Read more about the risks of a kidney transplant.

A healthy diet should include:

• at least 5 portions of fruit and veg a day
• plenty of potatoes, bread, rice, pasta and other starchy foods; ideally you should choose wholegrain varieties 
• some milk and dairy foods
• some meat, fish, eggs, beans and pulses, and other non-dairy sources of protein 

Avoid food that contains high levels of salt, as salt can cause high blood pressure, which can be dangerous for people with a kidney transplant. See facts about salt for more information and advice.

Exercise and weight loss

Once you've started to recover from the effects of surgery, you should try to do regular physical activity.

Adults should do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity exercise every week. This includes any activity that increases your heart and breathing rate – it may make you sweat, but you are still able to hold a normal conversation.

Examples include:

• fast walking
• riding a bike on level ground or with few hills
• swimming
• tennis

Choose physical activities that you enjoy, as you're more likely to continue doing them.

It's unrealistic to meet these exercise targets immediately if you have not exercised much in the past. You should aim to start gradually and then build on it.

If you're overweight or obese, you should try to achieve a healthy weight. This can be safely done through a combination of eating a healthy, calorie-controlled diet and regular exercise. Aim for a body mass index (BMI) of 18.5 to 25.

Read more about exercise and losing weight safely.

Alcohol, drugs and medications

Regularly drinking alcohol above the maximum recommended limits can raise your blood pressure, which can be dangerous for people with a kidney transplant. To keep your risk of alcohol-related harm low, the NHS recommends:

• not regularly drinking more than 14 units of alcohol a week
• spread your drinking over 3 days or more if you drink as much as 14 units a week
• it's a good idea to have several alcohol-free days each week

Read more about alcohol units and get tips on cutting down your alcohol consumption.

Alcohol is also high in calories, so you'll gain weight if you drink regularly. Being overweight will also increase your blood pressure. Read more about the calories in alcohol.

You should also avoid taking any illegal drugs after a kidney transplant, as they can damage your kidneys, cause a sudden rise in blood pressure and react unpredictably with your immunosuppressant medications.

Finally, always check with your care team before taking any medication, including over-the-counter medication and herbal remedies such as St John's wort. Some medications could be potentially harmful if you have had a kidney transplant and are taking immunosuppressant medication.

Immunosuppressants and infection

If you have a kidney transplant, you'll usually need to take immunosuppressant medications for the rest of your life to prevent your body's immune system from attacking the new kidney.

Widely used immunosuppressants include tacrolimus, ciclosporin, azathioprine, mycophenolate, prednisolone and sirolimus.

However, taking immunosuppressive medications on a long-term basis will weaken your immune system and make you more vulnerable to infections, so you'll need to take extra precautions against infection:

• avoid contact with people you know currently have infections, such as chickenpox or flu
• practise good personal hygiene – wash your hands regularly with soap and hot water, particularly after going to the toilet and before preparing food and eating meals

• if you cut or graze your skin, clean the area thoroughly with warm water, dry it, then cover it with a sterile dressing

  Make sure your vaccinations are up to date, although you won't be able to have any vaccines that contain live viruses, such as the measles, mumps and rubella (MMR) vaccine.

When to get medical advice

If you think you may have an infection, contact your GP or transplant centre for advice. Prompt treatment may be required to prevent serious complications developing.

Symptoms of infection can include:

• a high temperature of 38C or above
• feeling hot and shivery
• headache
• aching muscles
• diarrhoea
• vomiting

Although rates of serious complications have fallen sharply in the last few decades, kidney transplants – like any other type of surgery – are not risk-free.

The risks of a kidney transplant include:

• risks related to the procedure itself
• risks related to the use of immunosuppressant medications (which reduce the activity of your immune system)
• risks related to something going wrong with the transplanted kidney

Most complications occur in the first few months after a transplant, but can develop after many years.

Some of the main short-term and long-term complications of a kidney transplant are outlined below.

Short-term complications

Infection

Minor infections, such as urinary tract infections (UTIs), colds and flu, are common after kidney transplants.

Potentially more serious infections, such as pneumonia and cytomegalovirus (CMV), can occur and may require hospital treatment.

Blood clots

Blood clots can develop in the arteries that have been connected to the donated kidney. This is estimated to occur in around 1 in 100 kidney transplants.

In some cases, it may be possible to dissolve the blood clots using medication, but it's often necessary to remove the donated kidney if the blood supply is blocked.

Narrowing of an artery

Narrowing of the artery connected to the donated kidney, known as arterial stenosis, can sometimes occur after a kidney transplant. In some cases, it can develop months, or even years, after the transplant.

Arterial stenosis can cause a rise in blood pressure. The artery often needs to be stretched to widen it, and a small metal tube called a stent may be placed inside the affected artery to stop it narrowing again.

Blocked ureter

The ureter (the tube that carries urine from the kidney to the bladder) can become blocked after a kidney transplant. It can be blocked soon after the transplant – by blood clots, for example. It can also be blocked months or years later, usually due to scar tissue.

It may be possible to unblock the ureter by draining it with a small tube called a catheter. Sometimes surgery may be required to unblock the ureter.

Urine leakage

Occasionally, urine may leak from where the ureter joins the bladder after surgery. This usually occurs during the first month after the procedure. The fluid may build up in the tummy or leak through the surgical incision.

If you develop a urine leak, you'll usually need to have further surgery to repair it.

Acute rejection

Acute rejection means the immune system suddenly begins to attack the donated kidney because it recognises it as foreign tissue.

Despite the use of immunosuppressants, acute rejection is a common complication in the first year after a transplant, affecting up to 1 in 3 people.

In many cases, acute rejection does not cause noticeable symptoms, and is only detected by a blood test.

If it does occur, it can often be successfully treated with a short course of more powerful immunosuppressants.

Long-term complications

Immunosuppressant side effects

Immunosuppressants prevent your body's immune system from attacking the new kidney, which would cause the transplanted kidney to be rejected.

A combination of 2 or 3 different immunosuppressants is usually taken long term.

These can cause a wide range of side effects, including:

• an increased risk of infections
• an increased risk of diabetes
• high blood pressure
• weight gain
• abdominal pain
• diarrhoea
• extra hair growth or hair loss
• swollen gums
• bruising or bleeding more easily
• thinning of the bones
• acne
• mood swings
• an increased risk of certain types of cancer, particularly skin cancer

The doctor in charge of your care will be trying to find the right dose that is high enough to "dampen" the immune system to stop rejection, but low enough that you experience very few or no side effects.

Finding the optimal dose to achieve both goals is often a difficult balancing act. It may take several months to find the most effective dose that causes the least amount of side effects.

Side effects should improve once the right dosage is identified. Even if your side effects become troublesome, never suddenly stop taking your medication because your kidney could be rejected. Speak to your GP or transplant team for advice.

Diabetes

Diabetes is a common complication of having a kidney transplant.  

Diabetes is a lifelong condition that causes a person's blood sugar level to become too high. Some people develop it after a kidney transplant because, as they no longer feel unwell, they eat more and gain too much weight. Some types of immunosuppressants can also make you more likely to develop diabetes.

Symptoms of diabetes include:

• feeling very thirsty
• going to the toilet to urinate a lot, especially at night
• tiredness

Diabetes can often be controlled using a combination of lifestyle changes, such as alterations to your diet, and medication. 

Read more about treating diabetes.

High blood pressure

High blood pressure is also a common long-term complication of a kidney transplant.

Many people who need a kidney transplant already have an increased risk of developing high blood pressure, and taking immunosuppressants can make the condition worse.

High blood pressure doesn't usually cause any noticeable symptoms, but it can increase your risk of developing other serious conditions, such as heart disease, heart attacks and strokes.

Because of the risk of high blood pressure, you'll have your blood pressure checked at your follow-up appointments. You can also check your own blood pressure at home with a simple device available from most pharmacies. Read more about testing your blood pressure.

Cancer

The long-term use of immunosuppressants also increases your risk of developing some types of cancer, particularly types known to be caused by viruses (as you will be more vulnerable to the effects of infection).

These include:

• most types of skin cancer – including melanoma and non-melanoma
• Kaposi's sarcoma – a type of cancer that can affect both skin and internal organs
• lymphoma – a cancer of the lymphatic system 

You can reduce your risk of skin cancer by avoiding exposure to the sun during the hottest part of the day and by applying sun cream to your lips and all exposed areas of your skin every day.

Your care team can give advice on your individual risks, whether you need regular check-ups, and any early signs to look out for.