Diagnosing autosomal dominant polycystic kidney disease 

Autosomal dominant polycystic kidney disease (ADPKD) tends to be diagnosed in adults aged over 30 because symptoms don't usually develop until this stage.

When making a diagnosis, your GP will ask about your symptoms and your family’s medical history. If your kidneys are enlarged, your GP may be able to feel them in your tummy (abdomen).

Your GP may also arrange for some of the tests described below to be carried out.

Urine and blood tests

Your GP will measure your blood pressure to see if it is higher than normal. They may also carry out other tests, such as:

  • urine tests – to check for blood or protein in your urine
  • blood tests – to allow an estimate of the rate that your kidneys are filtering your blood to be made

GFR blood test

An effective way of assessing how well your kidneys are working is to calculate your glomerular filtration rate (GFR). GFR is a measurement of how many millilitres (ml) of blood your kidneys can filter out waste products in a minute. A healthy pair of kidneys should be able to filter more than 90ml per minute.

It is difficult to measure GFR directly, so it is estimated using a formula. The result is called the estimated GFR or eGFR. Calculating your eGFR involves taking a blood sample and measuring the levels of a waste product called creatinine, taking into account age, gender and ethnic group.

If your creatinine levels are higher than normal, it suggests your kidneys may not be filtering the blood as effectively as they should be. A low eGFR rate (15-29ml per minute) would suggest your kidneys are failing. At an eGFR of less than 10ml per minute, renal replacement treatment with dialysis or kidney transplantation is needed.

Read our page on diagnosing kidney disease for more information about what eGFR results mean.

Scans

Your doctor will also arrange for you to have an ultrasound scan to look for cysts in your kidneys or other organs, such as your liver. 

This is a painless procedure that involves passing a probe across the skin over your kidneys. The probe emits high-frequency sound waves that are used to create an image of the inside of your body.

In some cases, your doctor may arrange a computerised tomography (CT) scan or a magnetic resonance imaging (MRI) scan for you. These show the kidney in more detail.

If you have a family history of brain aneurysms, you will be advised to have a MRI scan. A brain aneurysm is a bulge in one of the blood vessels in the brain that is caused by a weakness in the blood vessel wall. 

Read more about diagnosing brain aneurysms.

Screening

Screening people known to be at risk of developing ADPKD due to a family history of the condition is a controversial issue in the medical community.

Some argue that screening achieves little, as there is currently no treatment to stop ADPKD developing.

Telling a person that they have ADPKD and are likely to develop kidney failure later in life could also cause a lot of stress and anxiety.

Other experts argue that although you can't prevent ADPKD, you can treat the high blood pressure (hypertension) associated with the condition, which may reduce the person's risk of developing cardiovascular disease. If the diagnosis is known, complications will not come as a surprise and can be treated promptly and appropriately. 

If you are considering being screened for ADPKD, or are considering having your children screened for the condition, discuss the advantages and disadvantages of screening with your GP, partner and family.

How screening is performed

There are two methods used to confirm a diagnosis of ADPKD. These are:

  • using an ultrasound, CT or MRI scan to check for any kidney abnormalities
  • in special circumstances, using genetic blood tests to determine whether you have inherited one of the genetic faults known to cause ADPKD in your family – however, these genetic tests are very expensive and can be difficult to interpret, so are not routinely performed

However, it's important to be aware that neither test is entirely accurate and they may not always detect ADPKD, even if you do have the condition..

Page last reviewed: 09/06/2014

Next review due: 09/06/2016