Have you noticed changes in your urine and wondered what they mean? If you live with immunoglobulin A nephropathy (IgAN) or another form of chronic kidney disease (CKD), your kidney care team may have talked with you about signs that could show you have protein in your urine. This is called proteinuria or albuminuria.

Learning what protein in your urine means — and how doctors check for it — can help you better understand your kidney health. With this knowledge, you can have more informed conversations with your healthcare provider about your kidneys and explore which treatment options may be right for you.

Protein in the Urine and IgA Nephropathy

Your kidneys normally filter waste and extra fluid from your blood while keeping important substances your body needs. One of these substances is albumin, a common protein in your blood. When your kidneys are healthy, they keep albumin in your blood, where it belongs. If the kidney filters are damaged, albumin can leak into your urine. This is called proteinuria (or albuminuria), and it can have several causes.

In IgAN, the body makes an abnormal version of the immune protein immunoglobulin A (IgA) that doesn’t function properly. These IgA proteins build up in the kidney’s filters, called the glomeruli — tiny clusters of blood vessels that clean your blood. The buildup causes inflammation and damages these filters. When the glomeruli are damaged, they cannot keep proteins like albumin inside your bloodstream, so albumin may leak into the urine.

In general, the more protein you have in your urine, the more kidney damage there may be. Doctors will likely check on a regular basis whether there’s protein in your urine and, if so, how much. This helps them understand how IgA nephropathy is affecting your kidneys. Treatments can help lower the amount of protein in your urine and protect your kidney function. If proteinuria gets worse, it can increase your risk for kidney failure. Doctors can also use your protein levels to help predict your risk of kidney failure and to plan the best care for you.

Are There Visible Signs of Protein in the Urine?

Sometimes, you may notice changes in your urine that could be signs of proteinuria, but these signs are not always reliable. Some doctors may suggest looking for foamy urine, which can look bubbly, frothy, or fizzy.

However, this sign can be confusing. Some people have bubbly urine from time to time, even if their kidneys are healthy. Sometimes, the bubbles may cover much of the surface of the toilet. If this happens to you, it may help to look at how many layers of bubbles you see. More than one layer of small bubbles is more likely to mean there is protein in your urine, compared to just a single layer of larger bubbles.

It’s important to remember that foamy urine can have other causes besides kidney problems, including:

• Dehydration
• Intense exercise
• High intake of protein
• Urinary tract infections
• Semen in the bladder
• Certain medicines

Most of these causes are temporary or can be treated easily. Foamy urine doesn’t always mean you have proteinuria.

If you notice foamy urine all or most of the time, talk with your doctor. This is especially important if you also have other symptoms linked to IgA nephropathy. Your doctor can help figure out what is going on and suggest the right next steps.

Common Symptoms That May Occur Alongside Protein in the Urine

Other symptoms of IgA nephropathy can happen along with protein in your urine. If you notice any of the symptoms below — especially if your urine is also foamy — it’s important to talk with your doctor. Watch for:

• Swelling in your hands, feet, face, or belly
• Blood in your urine, which may make it look darker or the color of tea or cola
• Hypertension (high blood pressure)
• Pain in your back, just below your ribs, on one or both sides
• A feeling of tiredness or weakness for no clear reason

If your symptoms change or get worse, let your nephrologist (kidney doctor) know. They can check how well your kidneys are working and help you find ways to protect your kidney function for as long as possible. Treatment often focuses on reducing the amount of protein in your urine.

How Nephrologists Detect Protein in the Urine

Doctors use different tests to check for protein in your urine. These tests are often done along with others to help understand how well your kidneys are working.

Dipstick Test

One of the simplest tests for proteinuria is the dipstick test. You give a urine sample, and your doctor dips a special strip (the dipstick) into the sample. The dipstick changes color if there is protein in your urine. Your doctor then compares the color of the dipstick to a chart to see how much protein is present.

Sometimes, doctors may want you to collect urine samples over 24 hours. This 24-hour urine test measures how much protein is in your urine during a full day, which can be more accurate than a single urine sample. Your doctor will give you step-by-step instructions for collecting your urine at home. Tracking your protein levels over time helps your doctor see if there are changes and adjust your care if needed.

If you notice your test results are changing or trending upward, talk with your doctor. They can help you understand what these changes mean for your kidney health and discuss next steps if needed.

Urine Albumin-to-Creatinine Ratio Test

Another important test is the urine albumin-to-creatinine ratio (uACR) test. For this test, you provide a one-time urine sample that is sent to a lab. The lab measures the amount of albumin compared to the amount of creatinine (a waste product that is normally in your urine).

Albumin isn’t usually found in the urine, whereas creatinine is, so the uACR test results give your doctors more information about how well your kidneys are working and whether they’re keeping albumin out of your urine.

Generally, a healthy result is less than 30 milligrams of albumin per gram of creatinine. Results between 30 and 300 milligrams per gram mean you have a moderate amount of protein in your urine. More than 300 milligrams per gram means you have a high level of protein in your urine.

Your doctor may ask you to repeat the test in three to six months to confirm the results. If the protein in your urine stays high, your doctor will want to monitor your kidney health more closely.

Overall Kidney Function Tests

Your doctor may order additional kidney tests if:

• You consistently have protein in your urine.
• Your protein levels in urine are going up.
• You already have IgAN and test positive for proteinuria.

These tests help you and your doctor see how well your kidneys are working and whether you might need more treatment to help protect your kidney function.

For instance, your doctor may order a blood test called the estimated glomerular filtration rate (eGFR). This test shows how well your kidneys are filtering waste from your blood.

In some cases, your doctor may recommend a kidney biopsy. This means taking a tiny sample of your kidney tissue and looking at it under a microscope. For IgA nephropathy, a kidney biopsy is the only way to confirm the diagnosis. The biopsy also helps your doctor understand how much damage there is and make a plan for your treatment that fits your needs.

Talk to Your Doctor if You Notice Changes

If you’ve noticed changes in your urine or are living with a kidney condition like IgAN, don’t wait to speak with your healthcare provider. Regular monitoring can help catch issues early and keep your kidneys working as well as possible for as long as possible. With the right care and support, you can take steps to manage protein in your urine and protect your overall kidney health.

Join the Conversation

On MyIgANteam, people share their experiences with IgAN, get advice, and find support from others who understand.

What signs of protein in your urine did you experience before you were diagnosed? Let others know in the comments below.