Albuminuria

Having albuminuria means there is slightly too much protein (specifically, albumin) in your pee (urine). This can be an early sign of kidney disease. Albuminuria is often a complication of diabetes and other health conditions.

About albuminuria

Albumin is a protein in your blood. Your kidneys filter your blood to remove waste products. These waste products then leave your body in your pee (urine). With healthy kidneys, very little protein passes into your pee. But if the filters in your kidneys are damaged, more protein can get through. This is sometimes called proteinuria. You might also hear it called microalbuminuria, which means the increase in albumin is relatively small.

Even a small amount of albumin in your urine may be an early sign of long-lasting (chronic) kidney disease. Along with other tests, doctors use your albumin level to diagnose kidney disease. They can also use these tests to estimate how quickly your condition may progress.

An increased level of protein in your pee can also mean you have an increased risk of heart attacks and stroke. Finding this out can help doctors to monitor you for these conditions and treat them earlier if you have them.

Causes of albuminuria

Kidney damage causes albuminuria. This might happen if you:

• have a kidney condition called glomerulonephritis (this affects the filters (glomeruli) in your kidneys)
• have diabetes (type 1 or type 2)
• have high blood pressure
• are very overweight (obesity)

Other things can temporarily raise the level of protein in your pee. These include:

• vigorous exercise
• having a fever
• a urine infection

Symptoms of albuminuria

You usually won’t notice any symptoms with only a small amount of protein in your urine (pee). This is because the protein levels aren’t high enough to cause symptoms.

You may start to have symptoms when the levels of protein in your pee get higher. At this stage, your pee may become foamy. If your kidneys become very damaged, this is called nephrotic syndrome. You may develop swelling in the ankles, hands or tummy, or puffiness around your face.

Because a small amount of protein in the urine doesn’t usually cause symptoms, it’s important to have regular tests if you’re at risk. If you have diabetes, for example, you should have a test for albuminuria once a year.

Diagnosis of albuminuria

The only way to diagnose albuminuria is to test a sample of your pee (urine) for albumin. Your doctor will ask you to have a test every year if you have diabetes or high blood pressure.

Your doctor may also offer you a test if you:

• have a health condition that affects your heart or blood vessels
• have a health condition that affects your kidneys
• have a kidney injury
• are taking medicines that affect your kidneys
• have been diagnosed with gout
• have a family history of kidney disease
• have had a positive test for blood in your urine

The albuminuria test

Doctors use the ACR test to diagnose albuminuria. ACR stands for albumin-to-creatinine ratio. The test can screen for albuminuria and spot it early. The ACR test measures whether you have signs of kidney disease. It compares the amount of albumin in your pee with the amount of creatinine. Creatinine is a waste product produced by your muscles. You’ll need to give your doctor a sample of your pee (urine), usually from first thing in the morning. They will send this to a laboratory for testing.

If your ACR is moderately increased, your doctor will ask you to have another test to confirm this. That will show whether your ACR has stayed high or gone back to normal since your first test. Your ACR can rise and fall daily, and a variety of things can affect the test results. For more information, see our section on causes of albuminuria.

Your GP will use the results of the ACR test and blood tests, to check for chronic kidney disease.

Complications of albuminuria

Albuminuria is an early sign that you may be developing long-lasting (chronic) kidney disease. It also shows that you are at increased risk of heart problems.

You can have albuminuria for some years without it getting any worse. It can even get better in some people. But without treatment, you are more likely to develop worsening kidney disease.

Long-term complications of kidney disease include problems with your heart and blood vessels. Chronic kidney disease can also cause problems with your bones, nerves and muscles.

With advanced kidney disease, your kidneys don’t work well enough to keep you well. You need treatment that replaces the role of your kidneys. This could include a kidney transplant or dialysis treatment.

It can take years for kidney disease to progress to this stage. And it only happens in a small number of people with kidney problems. Albuminuria is the first sign that your kidneys are being damaged. Treatment and lifestyle changes can help slow down and reduce this risk.