Diabetic nephropathy has five stages that describe the progression of the disease from least to most severe.
Diabetic nephropathy, also known as diabetic kidney disease, is a slowly progressing condition that may affect people who have type 1 or type 2 diabetes. It progresses in stages ranging from 1, the mildest, to 5, the most severe.
The high level of glucose in your blood that’s associated with diabetes can thicken and scar the small blood vessels in your kidneys. This damage prevents your kidneys from filtering waste from your blood. It could result in the leakage of the protein albumin into your urine.
Getting regularly screened for diabetic nephropathy is important if you have diabetes, especially since its earliest stages usually have no symptoms. Early detection and treatment may help slow or stop the progression of this disease.
Read on to learn more about the symptoms and treatment for each stage of diabetic nephropathy.
Diabetic nephropathy progresses in stages that are generally determined by:
- Glomerular filtration rate (GFR): Your estimated GFR measures creatinine, a kidney waste product, in your blood. The GFR ranges from over 90% in stage 1 to lower than 15% in stage 5.
- Urine albumin-creatinine ratio (uACR): UACR indicates the amount of the protein albumin in your urine. An uACR of over 30 for at least 3 months, called albuminuria, indicates kidney damage.
- Blood pressure: Doctors also take into account how much your blood pressure is elevated.
Some damage to your kidneys is present during stage 1 diabetic nephropathy, but they are still functioning. By stage 5, kidney failure occurs. Dialysis or a kidney transplant is needed to live.
Stage 1 is the earliest and mildest stage of diabetic nephropathy.
Your GFR is above 90%, meaning your kidneys are still functioning at between 90% and 100% of their capacity.
If your uACR is 30 or less, there’s a low risk of your diabetic nephropathy getting worse. If it’s above 30, the risk of diabetic nephropathy worsening is greater. There’s also an increased risk of heart disease.
Treatment at this stage may help prevent disease progression.
Diabetic nephropathy stage 1 symptoms
You probably won’t notice any symptoms during stage 1. The following are some of the symptoms of diabetic nephropathy in its early stages:
- foamy urine, indicating the presence of albumin
- occasional fatigue
- somewhat elevated blood pressure
Stage 1 treatment
To prevent diabetic nephropathy from progressing further, stage 1 treatment may include:
- making lifestyle changes, like stopping smoking if you smoke, getting regular exercise, and eating a diet low in sodium and protein
- taking metformin (Fortamet, Glucophage, others) to reduce your blood sugar levels and prevent kidney failure
- taking angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) to lower your blood pressure and the amount of albumin in your urine
In stage 2 diabetic nephropathy, your GFR is between 60% and 89%, and your uACR has been 30 or higher for at least 3 months.
Mild damage to your kidneys is present, with some loss of function.
Diabetic nephropathy stage 2 symptoms
As with stage 1, you may have no symptoms, or you may experience:
- foamy urine
- occasional fatigue
- somewhat elevated blood pressure
Stage 2 treatment
The treatment for stage 2 diabetic nephropathy is usually the same as treatment for stage 1.
Your doctor may also prescribe sodium-glucose transport protein 2 (SGLT2) inhibitors to help increase glucose excretion in your urine and lower your blood sugar levels.
By stage 3 diabetic nephropathy, you may start to notice some symptoms. This is the first stage that can be diagnosed solely by your GFR rather than your GFR and uACR, although a uACR screening is still helpful.
Stage 3 is divided into two stages:
- Stage 3A: Your loss of kidney function is mild to moderate. Your GFR is from 45% to 59% for at least 3 months.
- Stage 3B: You have moderate to severe loss of kidney function, with a GFR of 30% to 44%.
Diabetic nephropathy stage 3 symptoms
- more or less frequent urination
- fatigue
- itchy or dry skin
- nausea
- loss of appetite
- difficulty concentrating
- sore or cramping muscles
- swelling or numbness in your arms, feet, ankles, or legs
- unintended weight loss
Stage 3 treatment
In addition to the treatments for earlier stages, prescription medications for stages 3A and 3B may include:
- GLP-1 receptor agonists to manage blood sugar levels
- finerenone (Kerendia) to slow kidney damage and reduce tissue scarring
- statins to lower cholesterol levels and reduce the risk of stroke or heart attack
If you have high blood pressure, your doctor may recommend limiting your total daily sodium intake to 2,300 milligrams, about 1 teaspoon, or less.
Avoid taking nonsteroid anti-inflammatory drugs (NSAIDs) like ibuprofen (Motrin, Advil) or naproxen (Aleve, Naprosyn). These drugs may cause further harm to your kidneys.
In stage 4 diabetic nephropathy, there is severe loss of kidney function. Your GFR is between 15% and 29% for 3 months or more.
In addition to being at the highest risk for kidney failure, in stage 4 you are also have a very high risk of heart disease.
Diabetic nephropathy stage 4 symptoms
You are likely to experience symptoms during stage 4 diabetic nephropathy.
In addition to the symptoms of earlier stages, stage 4 symptoms may include:
- breath that smells fishy or like ammonia
- trouble sleeping
- shortness of breath
Stage 4 treatment
Along with the treatments for earlier stages, treatments to help slow the progression of diabetic nephropathy to stage 5 may include:
- treatment for anemia, if you have it
- management of bone and mineral disorders (hyperphosphatemia), if they develop
- planning for vascular access if you may need hemodialysis
At this stage, various specialists, including an endocrinologist, dietitian, or nephrologist, may be part of your care team.
Stage 5 diabetic nephropathy, also called end stage renal disease (ESRD) or kidney failure, is the final and most serious stage of diabetic nephropathy.
Your GFR is 15% or lower, meaning your kidneys are functioning at less than 15% of their capacity.
Diabetic nephropathy stage 5 symptoms
You may experience the following symptoms in addition to those of earlier stages:
- chest pain or pressure
- confusion
- drowsiness
- seizures, in extreme cases
Stage 5 treatment
Along with medications and lifestyle changes, the treatment for stage 5 diabetic nephropathy may focus on replacing your kidney function.
This may involve:
- hemodialysis
- peritoneal dialysis
- kidney transplantation
Your doctor may also provide:
- medication to manage your pain
- psychological support referral
- palliative care
The amount of time it takes for diabetic nephropathy to progress varies.
Kidney changes like thickening of the nephrons may begin about 1.5 to 2 years after receiving a diagnosis of type 2 diabetes.
The increase of albumin in urine and reduction of glomerular filtration rate may start occurring
A 2020 study found that 10% to 17% of 65,731 people with type 2 diabetes experienced worsening kidney disease over a 2-year period.
The factors that may increase the speed of progression include:
- obesity
- hypertension (high blood pressure)
- anemia
- heart failure
- dyslipidemia (high levels of lipids in your blood)
- proteinuria (high levels of protein in your urine)
- being over 80 years old
A diagnosis of diabetic nephropathy is
The diagnosis is based on the following screening tests that measure the albumin in your urine and GFR in your blood:
Kidney damage from diabetes can’t be reversed. However, you can
- getting blood and urine tests every year to check your kidney function
- getting your hemoglobin A1c level tested up to four times per year or at least twice yearly
- taking prescribed medications to manage your blood sugar levels
- getting regular physical activity
- eating more fruits and vegetables and following a diet that’s low in protein, salt, phosphorus, and potassium
- losing weight if you have overweight or obesity
- quitting smoking, if you smoke
If you receive a diagnosis of diabetic nephropathy, you can take medications and make lifestyle changes to help slow or stop the progression of kidney damage and maintain a good quality of life.
The outlook for people with early stages of diabetic nephropathy is typically positive since blood sugar and blood pressure can be managed to avoid more kidney damage.
By stages 3 and 4, there’s an increased risk of complications like heart disease, but treatment may still slow the progression.
The outlook for stage 5 is less favorable. Dialysis or a kidney transplant is needed to survive at this stage.
If you have diabetes, it’s important to have blood and urine tests every year to detect diabetic nephropathy in its earliest stages.
The earlier diabetic nephropathy can be diagnosed, the better the chance of slowing or stopping kidney damage.