Diabetic kidney disease is kidney damage caused by diabetes over time. It rarely causes symptoms until it is advanced, so a yearly urine albumin test and eGFR blood test are the way to find it early. Good blood sugar, blood pressure below 130/80 and kidney protecting medicines can slow it a lot.
By the Nyrami editorial teamPublished 13 August 2026Updated 2 October 20268 min read
Diabetes is one of the two most common causes of kidney failure in Norway, and more than a third of the people who start dialysis or receive a new kidney have diabetes. At the same time, kidney damage from diabetes is among the things we can now slow down best, especially when it is found early. Here is what you should know, whether you have diabetes yourself or care about someone who does.
Diabetic kidney disease, also called diabetic nephropathy, is damage to the kidney filters caused by blood sugar being too high for a long time, often together with high blood pressure. The small blood vessels in the filters are damaged and start letting albumin into the urine. Albumin is a protein that should normally stay in the blood. Later, kidney function, measured as eGFR, may start to fall. It is one form of chronic kidney disease.
The first sign is usually albumin in the urine. Without treatment the leak increases over time in most people: the Norwegian Medicines Handbook (Norsk legemiddelhåndbok) states that moderately increased albumin in the urine progresses to clear kidney disease in more than eighty per cent of cases if it is not treated. With treatment the outlook is far better.
In Norway, diabetes was the cause in twenty-one per cent of the nearly 400 people registered with stage 5 kidney failure in the Norwegian Renal Registry in 2024, while high blood pressure was the cause in thirty-five per cent. But when you also count people who have diabetes alongside another kidney disease, thirty-six per cent of those who started dialysis or received a new kidney in 2024 had diabetes.
Without treatment, twenty to forty per cent of people with type 1 or type 2 diabetes will develop kidney damage, according to Norsk helseinformatikk. The risk grows the longer you have had diabetes, and it is higher when blood sugar and blood pressure are poorly controlled. Even so, most people with diabetes never get kidney failure, and only a few need dialysis or a new kidney.
Diabetic kidney disease usually causes no symptoms at first. You cannot feel albumin leaking into your urine, and you rarely notice eGFR falling until kidney function is greatly reduced. That is why you cannot wait for signs. It is the tests that find the disease.
When the disease is advanced, you may get swollen legs and ankles, tiredness, itching, poor appetite and nausea. Many also notice that their blood pressure becomes harder to bring down. Read more in Symptoms of kidney failure.
Foamy urine with diabetes can be a sign that a lot of protein is leaking. A little foam when you pass urine forcefully is common and harmless. But if your urine foams a lot every time for several days, you should have a urine test with your GP (fastlege). Read more in Foamy urine.
Everyone with diabetes should have two kidney tests every year: a urine test that measures albumin, and a blood test that gives eGFR. Helsedirektoratet (the Norwegian Directorate of Health) recommends a yearly urine test, more often if the disease is suspected to be progressing, and a yearly eGFR rather than creatinine alone.
The urine test is reported as the albumin to creatinine ratio (u-AKR, often called ACR in English) in mg/mmol. One raised result is not enough, because hard exercise, fever and urinary tract infections can also increase albumin in the urine. The diagnosis requires raised values in at least two out of three samples.
| u-AKR (mg/mmol) | What it means |
|---|---|
| Below 3 | Normal |
| 3 to 29 | Moderately increased albuminuria, often the first sign of kidney damage |
| 30 to 299 | Severely increased albuminuria |
| 300 or more | Nephrotic range proteinuria, a very large amount of protein in the urine |
Read more in Protein in urine, eGFR normal range and Blood tests in kidney disease. You can also work out your eGFR in the eGFR calculator.
For most people with type 2 diabetes the target is a long term blood sugar (HbA1c) of around 53 mmol/mol, which equals 7 per cent. If you have had diabetes for a long time, have heart or blood vessel disease or have an eGFR below 45, the target is often 53 to 64 mmol/mol, because the risk of low blood sugar (hypos) increases. You set the target together with your doctor.
Blood pressure should be below 130/80. With albumin in the urine this is especially important, and a goal in itself is that the albumin leak goes down or stays stable. Read more in High blood pressure and kidney disease.
No, metformin does not damage the kidneys. But metformin leaves the body through the kidneys, and when kidney function is reduced it can build up. That raises the risk of a rare but serious side effect called lactic acidosis. That is why metformin is adjusted according to eGFR.
| eGFR (ml/min/1.73 m²) | What Helsedirektoratet says |
|---|---|
| Above 60 | Can be used as usual |
| 45 to 60 | Can be used, with a lower maximum dose |
| 30 to 45 | Can be continued with a lower maximum dose, but new treatment should not be started |
| Below 30 | Should not be used |
The guidelines also say metformin should be paused when you become dehydrated from vomiting, diarrhoea or fever, and it may need pausing before scans that use contrast dye. Ask your doctor for a written plan, and do not stop or switch on your own.
There are now four groups of medicines shown to protect the kidneys in diabetes, and several of them also protect the heart. Which ones suit you depends on your eGFR, albumin in the urine, potassium and which type of diabetes you have.
Many people take several of these at once. Read more in Medicines in kidney disease and The kidneys and the heart. Also be careful with painkillers: anti-inflammatories such as Ibux (ibuprofen) can damage the kidneys, especially together with blood pressure medicine and water tablets. See Painkillers and the kidneys.
The best diet looks like the one that is good for blood sugar: plenty of vegetables, fish, wholegrain foods, little salt and little processed food. But when kidney function is reduced, some advice can pull in different directions.
There is no single answer that fits everyone. Ask for an appointment with a clinical dietitian if the advice you have been given feels contradictory.
The damage to the kidney filters usually does not reverse, but the albumin leak can go down with good treatment, and the fall in eGFR can be slowed a lot. Helsedirektoratet calls a fall in urine albumin a good sign in itself. Untreated, eGFR often falls by 5 to 6 ml/min a year when a lot of albumin leaks, so early treatment can save many years of kidney function. Also read Can kidney failure get better?.
You can remind them about the yearly check-up and go along to the doctor if the person you care about wants you to. It also helps to know the plan for which medicines to pause during vomiting, diarrhoea or fever, especially if you help an older parent with their medicines. Read more in Family and kidney disease.
In the Nyrami app you can log blood sugar, blood pressure, eGFR, creatinine and albumin and see them over time in one place, so you come prepared to your yearly check-up. The food scanner reads the barcode and assesses potassium, phosphorus, sodium and protein for you, and the recipes are assessed per portion. The app is free for iPhone and Android.
Turns the advice into something you can use in the shop and the kitchen: scan food and see potassium, phosphorus and salt assessed for you, and follow your numbers over time. Free on iPhone and Android.
What is good for your kidneys is the same as what is good for your heart: little salt, plenty of vegetables, fruit and wholegrains, water when you are thirsty, activity and no smoking. No food cleanses or repairs the kidneys. If you have kidney disease, the advice on potassium, phosphorus and protein may be different.
Dialysis cleans the blood of waste products and excess water when the kidneys can no longer do it themselves. Haemodialysis is usually done in hospital three times a week for about four hours, while peritoneal dialysis is done at home every day. The two forms work about equally well, and many people can have dialysis at home.
Healthy adults over 18 can be assessed as a kidney donor for a family member or close friend. The risk is small but not zero: a slightly higher risk of high blood pressure and kidney failure later in life. You are examined thoroughly, lost income is covered, and you can withdraw at any time.
