After diagnosis

If your results show that you have chronic kidney disease, your doctor should discuss the possible causes with you and agree a plan to find out the cause. This is especially important if the cause is likely to be treatable.

Categories of chronic kidney disease

Your doctor should use your test results to find out how serious your chronic kidney disease is and what this means for you.

Your doctor should work out your chronic kidney disease 'category' based on how well your kidneys are functioning (your 'G' category) and how much protein they are leaking into your urine (your 'A' category). The combination of these 2 categories will tell your doctor how severe your kidney disease is.

The G categories compare how well your kidneys are functioning with how well normal adult kidneys function. They roughly correspond to percentages, so, for example, G1 means your kidneys are functioning 90% or more as well as normal kidneys. The categories are as follows:

  • G1 – your kidneys are functioning normally (90% or more)

  • G2 – your kidneys are functioning slightly worse than normal (60–89%)

  • G3a – your kidneys are functioning slightly to moderately worse than normal (45–59%)

  • G3b – your kidneys are functioning moderately to much worse than normal (30–44%)

  • G4 – your kidneys are functioning much worse than normal (15–29%)

  • G5 – your kidneys are at risk of failing or have failed (less than 15%).

The A categories show how much protein is leaking from your kidneys into your urine. If there is more protein than normal in your urine, it can indicate damage to your kidneys:

  • A1 – your kidneys leak a normal or slightly increased amount of protein

  • A2 – your kidneys leak a moderately increased amount of protein

  • A3 – your kidneys leak a severely increased amount of protein.

The G category and A category are then combined to describe your kidney disease (for example, G2A3 or G4A1).

In both G and A categories, the higher the number, the worse your kidney disease is. For example, if your kidneys are functioning much worse than normal and leak a moderate amount of protein (category G4A2), you are at a higher risk of worsening disease and other related medical problems (particularly heart disease) than if your kidneys are functioning moderately worse than normal and leak a small amount of protein (category G3A1).

If your category is G1A1 or G2A1, then you do not have chronic kidney disease unless you have another problem that indicates kidney damage (such as kidney stones or blood in your urine). Categories G4 and G5 may sometimes be described as advanced chronic kidney disease; G5 is also known as kidney failure.

Your doctor should discuss your category and the related risks with you.

If your kidney disease is described using the old system of stages 1 to 5, these are the same as the 'G' categories G1 to G5.

Your doctor should discuss and agree with you how often you should have tests to check your kidneys depending on your chronic kidney disease category (see Checking for worsening disease).

Ultrasound scans

If you have been diagnosed with chronic kidney disease, you may be offered an ultrasound scan to help your doctor look for any problems with your kidneys. You should be offered an ultrasound scan only if:

  • your blood tests show that your kidney disease is worsening (progressing)

  • you have blood in your urine (visible or detected by a urine test)

  • you have symptoms of a urinary blockage (called a urinary tract obstruction)

  • you are aged over 20 years and have a family history of a kidney condition called polycystic kidney disease

  • you have advanced chronic kidney disease

  • your specialist thinks that you need a procedure called a kidney biopsy to further investigate your condition.

If someone in your family has kidney disease that may be hereditary (passed on through their family), your doctor should talk with you before the scan about what it might mean if you have an abnormal result.

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