This factsheet is for people who have been newly diagnosed with autosomal dominant polycystic kidney disease (ADPKD) and their families and carers. It covers the topics you’re likely to want to know more about to understand the disease and how it might affect you.
Getting a diagnosis of ADPKD can be a worrying time. If you’d like emotional support, practical advice and information, ring our confidential PKD Helpline 0300 111 1234 (9.30 am to 5.00 pm Mon to Fri, except bank holidays) or visit the Support section of our website.
- What is ADPKD?
- How common is ADPKD?
- How did I get ADPKD?
- How is ADPKD diagnosed and monitored?
- What problems does ADPKD cause?
- How is ADPKD treated?
- How will ADPKD affect my life?
- Looking for support?
- What can I do to help my kidneys?
- What is the chance of my child having ADPKD?
- Learn more from the PKD Charity
- Information from other organisations
- Authors and contributors
What is ADPKD?
Autosomal dominant polycystic kidney disease (ADPKD) is a genetic condition some people are born with. It causes cysts (balloons of fluid) to develop in your kidneys and sometimes in other organs. Kidney cysts grow over time. Each cyst can grow to a size anywhere between a pea and a grapefruit (Figure 1). Over the years, the cysts can damage much of your kidney tissue and make your kidneys become very large.
With the right care, most people stay in good health for decades after a diagnosis of ADPKD.
Figure 1: Drawing of the inside of a polycystic kidney (right), showing cysts of different sizes, compared with a normal kidney (left).
How common is ADPKD?
In the UK, it’s thought that between 1 person in every 1,000 to 2,500 has ADPKD. There could be between 30,000 and 70,000 people with the disease in the UK. ADPKD can affect men and women, and people of all ethnic backgrounds.
How did I get ADPKD?
ADPKD is usually inherited and occurs when gene alterations are passed from a parent to their child. Genes are the instructions our cells need to grow and divide to keep us healthy throughout our lives. We all have two copies of each gene, one from each parent.
ADPKD is most commonly caused by an alteration in a gene called PKD1 or a gene called PKD2.
Most people get the disease when they inherit an altered copy of PKD1 or PKD2 from a parent with ADPKD. PKD1 mutations are more common: about 78 out of every 100 people with ADPKD (78%) have an alteration in this gene. About 14 out of every 100 people (14%) have an altered PKD2 gene. Some people have an alteration in a different gene, or the genetic cause is unknown.
Sometimes, a new alteration in a PKD1 or PKD2 gene occurs by chance in the womb, causing an infant to be born with ADPKD despite having two healthy parents.
This is called a ‘spontaneous’ or ‘de novo’ mutation and occurs in about 1 in 10 people with ADPKD.
How is ADPKD diagnosed and monitored?
Kidney function is often assessed using ‘estimated glomerular filtration rate’, or eGFR. This is a measure of how many millilitres (ml) of waste fluid your kidneys can filter from your blood in one minute. eGFR is usually calculated using a blood test to measure levels of a waste product called creatinine in your blood.
Perfectly functioning kidneys have an eGFR of about 100-110 ml/min. The lower your eGFR is, the poorer your kidney function.
A value between 60 and 89 suggests mild kidney damage. A value between 15 to 60 means you have kidney disease, and a value under 15 means your kidneys are failing.
It can be useful to think of eGFR as a percentage. For example, an eGFR of 40 ml/min means your kidneys are working at roughly 40% the level of perfectly functioning kidneys.
eGFR is reasonably accurate but the results can fluctuate, especially if your kidney function is good. eGFR gets lower in all people as they get older. For example, many healthy people have an eGFR of about 80-85 ml/min by the age of 65-74.
ADPKD is typically diagnosed using an ultrasound scan. Ultrasound uses soundwaves to make an image of the inside of your body. Cysts and enlarged kidneys show up on the scan.
After diagnosis, you may have ultrasounds or other scans periodically to check the size of your kidneys. You may also have scans of your liver to check for cysts.
Blood and urine tests
After diagnosis, you’ll have periodic blood tests to check how well your kidneys are filtering your blood. These measure your estimated glomerular filtration rate (eGFR), which we explain below.
If your kidney function is poor or you’re on dialysis, you’ll have additional lab tests to check the balance of different substances in your blood that might need correction.
A urine test is usually done at the same time to check for other substances such as protein.
Magnetic resonance imaging (MRI)
MRI is a hospital scan that uses a magnet and radio waves to make images of the inside of your body. You might have MRI periodically to check how large your kidneys are and to estimate how much your disease has progressed. Alternatively, an ultrasound or computed tomography (CT) scan might be used.
Your blood pressure will need to be checked regularly so it can be treated if it becomes too high. A blood pressure test uses an air-filled cuff on your upper arm to measure the strength of your pulse. Many patients choose to check their blood pressure at home but your GP or practice nurse can check it too.
Blood pressure is a measure of how strongly blood pushes against your artery walls as your heart pumps blood around your body. It’s measured in millimetres of mercury (mmHg) and is recorded as two figures:
- systolic pressure: the pressure of the blood when your heart beats.
- diastolic pressure: the pressure of the blood between beats.
For example, if your blood pressure is 135/85, your systolic pressure is 135 mmHg and your diastolic pressure is 85 mmHg. Blood pressure consistently 140/90 mmHg or higher on separate occasions usually indicates high blood pressure.
Genetic testing is sometimes for a diagnosis of ADPKD. Not all adults with symptoms of ADPKD need a genetic test to confirm that they have the disease. However, you might have genetic testing if:
- You have symptoms of ADPKD and are below the age of 18 years.
- Your symptoms don’t match the classic symptoms of ADPKD.
- Results of genetic tests could help to plan your health care.
You’ll be under the long-term care of a specialist kidney doctor (nephrologist) and will see them for check-ups. Some people may be monitored by a GP if their kidney function is good and they have no complications.
How often you’re invited for check-ups depends on:
- how well your kidneys are working
- whether your treatment has recently changed
- any other health problems you have.
What problems does ADPKD cause?
Figure 2: The more common symptoms of ADPKD.
High blood pressure
ADPKD usually causes high blood pressure - known as hypertension. This can start in childhood, but most people with ADPKD get it in their 30s to 40s. Sometimes, it’s the first sign of ADPKD. Usually, high blood pressure doesn’t cause symptoms and so it’s picked up only by blood pressure tests.
It’s important to treat high blood pressure, as it can increase your risk of heart disease and might increase the speed of kidney damage.
Urinary tract infections
Urinary tract infections are quite common among people with ADPKD; about 3-5 in every 10 people get at least one in their lifetime. They’re more common in women.
Kidney and liver cysts can become infected with bacteria, usually from your gut. An infected cyst is usually painful and can cause a high temperature (fever). If you get these symptoms, see your doctor right away.
People with ADPKD are more likely than the general population to develop kidney stones, which can be painful. These are usually made of uric acid crystals.
Blood in your urine
About 6 in every 10 people with ADPKD get a bleeding cyst or blood in their urine (known as haematuria) at some point. Blood in the urine can happen for a variety of reasons, such as a cyst bleeding, a kidney stone, a cyst infection or damage to the kidney caused by a big knock. Blood in the urine usually gets better within a week without treatment. Often, the cause is not found.
Let your doctor know if you have blood in your urine. They can check your urine and refer you for further tests if needed.
Abdominal pain and bloating
If you have ADPKD, you’ll probably get cysts in your kidneys and liver, making these organs grow over time. The larger they get, the more space they’ll take up. Your abdomen (tummy) may become swollen and you may get abdominal or back pain, indigestion or feel full.
Six out of every 10 people with ADPKD have long-term pain (chronic pain). The first step to treating pain is to find the cause. When the cause can’t be resolved, medications, psychological approaches and manual therapies can help to manage pain.
Reduced kidney function
Our kidneys have several functions. They filter waste products and extra fluid from our blood and convert them into urine. They also help to control our blood pressure. Having ADPKD can make it harder for your kidneys to do these jobs.
Although ADPKD causes damage to the kidneys, any remaining healthy tissue will continue to work well, usually for decades. People with reduced kidney function usually only get symptoms when their kidney function becomes quite poor. Your kidney specialist will keep a close eye on your kidney function using blood tests and scans.
A failing kidney can only filter up to a sixth (15%) of the blood that a healthy kidney can. This is measured as an eGFR of 15 or less ml/min (see earlier for an explanation of eGFR).
Most people with ADPKD find that their kidneys fail between the age of 40 and 70 years old. In advance of this happening, you and your kidney specialist will plan for you to have a kidney transplant or start dialysis.
People with ADPKD are more likely to get a swollen small artery in the brain than people without ADPKD. This is called a brain aneurysm. Brain aneurysms may be more likely in people with ADPKD because the gene alterations that cause ADPKD might also affect blood vessels.
There’s a risk that these can bleed on the brain, but they can usually be treated before this happens. Treatment reduces the risk of them bleeding.
People with ADPKD who have kidney failure may also develop diverticular disease (where bulges form in the bowel wall) or hernias (where part of the bowel comes through the abdominal muscle)
How is ADPKD treated?
There is no cure for ADPKD, but treatments can help to reduce your symptoms and lower your risk of complications. For example, different medications can lower your blood pressure, treat infections or help to manage pain.
Some people need to have procedures or surgery, for example to drain and treat a large kidney cyst.
A drug called tolvaptan is suitable for some adults with ADPKD — this can slow the progression of ADPKD. Tolvaptan reduces the rate at which the kidneys become enlarged by cysts and can help to slow the decline of kidney function. Tolvaptan might be suitable for you if you have reduced kidney function and your ADPKD is progressing rapidly. Genetic testing is sometimes used to help decide whether tolvaptan treatment would help a patient.
If your kidneys fail, you’ll need treatment to take over some of their work. This is known as kidney replacement therapy. The best option is usually a kidney transplant, where you receive a donated kidney from a living or deceased donor. If this isn’t possible, or if you would prefer, you could have dialysis.
Haemodialysis uses a machine to filter your blood, whereas peritoneal dialysis uses a special fluid placed in your abdomen to absorb waste.
A kidney transplant will do about half (50%) of the work of a healthy kidney, while dialysis will do about one tenth (10%). Even a 10% increase in function will be enough to improve some of your symptoms.
What can I do to help my kidneys?
There are things you can do to help to protect your kidneys and stay as healthy as possible:
Smoking can increase the speed at which your ADPKD progresses and damages your kidneys.
It is also bad for your general health.
Take your blood pressure medication
If you have high blood pressure, it’s important to control it. High blood pressure increases the chance of having a heart attack or bleed on the brain (intracranial haemorrhage).
It can also cause your ADPKD to progress faster. Blood pressure can be treated with lifestyle changes and medications. Read more about blood pressure.
There is no recommended special diet that people with ADPKD should follow, but a balanced diet is important for everyone for controlling weight.
Being overweight or obese may lead to a faster decline in your kidney function and can increase your risk of high blood pressure or cardiovascular problems.
Limit how much salt you eat because salt makes high blood pressure worse and may increase the speed that your kidney function declines.
Regular exercise is an important part of a healthy lifestyle because it helps to control your weight and blood pressure.
There haven’t been any studies proving that drinking extra fluid slows the growth of kidney cysts.
For the moment, kidney experts recommend that you drink enough that you don't get thirsty, but not excessively.
Use pain medications other than NSAIDs
Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are commonly used for pain and inflammation. However, using them repeatedly or for a long time can damage the kidneys.
Long term use is generally not recommended for people with ADPKD, particularly if your kidney function is already impaired.
Ask your doctor or pharmacist to suggest safer alternatives for you.
What is the chance of my child having ADPKD?
People with ADPKD have one normal and one altered copy of a PKD gene. Which gene copy your child inherits is down to chance.
If you have ADPKD, there is a one in two (50%) chance you’ll pass the altered gene to your child. If they inherit the altered gene, they’ll have ADPKD too. This is known as a ‘dominant inheritance’.
Figure 3: Inheritance of ADPKD.
The diagram (Figure 3) shows each parent’s chromosomes (in grey) that carry a PKD gene (either PKD1 or PKD2) with the normal gene in green and the altered gene in purple. The child will inherit one of these genes on a chromosome from the father and one on a chromosome from the mother.
The lower half of the diagram shows the different ways that the parents’ genes could be passed to their child. In the scenario on the left, the child inherits the altered gene (purple) from the affected parent, and a normal gene from the other parent. This child will have ADPKD. In the scenario on the right, the child inherits a normal gene (green) from each parent and will not have ADPKD.
You can read more about the genes involved in ADPKD and how you can be tested for them in our factsheet Genetic counselling and genetic testing in ADPKD.
Learn more from the PKD Charity
You can find support and further information about ADPKD and living with the disease on the PKD Charity’s website; or see the links throughout this factsheet.
Download our free, self-help PKD App created to inform and educate people who are newly diagnosed or at early stages of autosomal dominant polycystic kidney disease (ADPKD).
Information from other organisations
You might find the following organisations and websites useful:
- Kidney Research UK has information on the latest research into all forms of kidney disease.
- Kidney Care UK provides grants and other financial support to all kidney patients.
- The National Kidney Federation has local kidney patient groups associated with kidney units in hospitals around the UK.
- The NHS website has health information on a wide range of topics.
- RaDaR Registry is a UK-wide registry of adults and children with rare kidney diseases including ADPKD. If you’re interested to join the registry, please ask your kidney doctor for more information, or visit the website.