People with immunoglobulin A nephropathy (IgAN) often notice swelling in their feet or ankles. This swelling, called edema, is caused by a buildup of fluid and is a common sign of proteinuria, which means there’s too much protein in the urine. Edema can show up in different parts of the body, including the face, belly, legs, or feet.

Proteinuria is a sign that the kidneys’ filtering system isn’t working properly. Normally, healthy kidneys balance fluids and electrolytes (minerals) while keeping important proteins in the bloodstream. But when the kidneys are damaged or scarred — as they often are with IgAN — they can’t filter correctly. This allows protein to leak into the urine and causes the body to hold on to fluid.

While it might seem like swelling happens just because of fluid buildup, it’s actually a combination of protein loss and kidney damage that leads to edema in IgAN.

In this article, we’ll explore why swelling happens with proteinuria, what it means for your kidney health, and how you can manage it.

How Proteinuria Can Lead To Swelling

In IgA nephropathy, inflammation damages the glomeruli, the tiny blood vessels in the kidneys that help filter waste and fluid from your blood. Healthy glomeruli keep important proteins, like albumin, in the bloodstream. But when these filters are damaged, protein can leak into the urine, leading to proteinuria.

When proteinuria occurs along with other specific symptoms due to damage to the glomeruli, the condition is known as nephrotic syndrome. Nephrotic syndrome can develop as a complication of kidney diseases like IgAN.

Common signs and symptoms of nephrotic syndrome include:

• High levels of protein in the urine
• Low levels of albumin (called hypoalbuminemia) and other proteins in the blood
• Swelling around the eyes, ankles, and hands
• Hyperlipidemia (high cholesterol levels)

In nephrotic syndrome, a large amount of protein is lost in the urine instead of staying in the blood. Protein, especially albumin, helps hold fluid inside blood vessels. When the blood has too little albumin, its ability to retain fluid drops. This causes fluid to leak out of the blood vessels into surrounding tissues, leading to noticeable swelling in the face, hands, feet, and belly.

Possible Complications of Proteinuria and Swelling

When fluid leaks from your blood vessels into nearby tissues, the blood remaining inside your blood vessels is thicker than normal. This thicker blood doesn’t flow as easily and can increase your risk of developing blood clots, especially in deep veins — a condition known as deep vein thrombosis (DVT).

Blood clots are most common in the legs and pelvis, but they can also form in other areas. People with IgAN have a higher risk of DVT, especially in the legs or kidneys.

Why Swelling Might Get Worse

In adults, swelling from proteinuria often begins around the eyes and in the legs. As nephrotic syndrome progresses, the swelling can spread and may lead to unexplained weight gain.

Swelling that worsens over time can be a sign that your kidney function is declining. You might also notice other symptoms linked to proteinuria, such as:

• Foamy or bubbly urine
• Muscle cramps, especially at night
• A need to urinate more often than usual
• Nausea or feeling sick to your stomach

If your swelling increases or you notice any of these symptoms, contact your doctor as soon as possible. Treating the underlying cause — like proteinuria from IgAN — early can help protect your kidney health.

Evaluating Swelling With Proteinuria

If you’re experiencing swelling in your face, legs, or feet — especially along with other signs of proteinuria — your doctor or nephrologist (kidney specialist) may order tests to see whether your symptoms are related to kidney disease.

Urine Tests

The evaluation usually begins with a urine dipstick test, which checks for protein in a single sample of urine. This quick test can show whether protein is present, but it isn’t always precise.

To get a clearer picture, your doctor may order a urine albumin-to-creatinine ratio (UACR) test. This test compares the amount of albumin (a key blood protein) to creatinine (a waste product from muscles) in your urine. A higher ratio may suggest that your kidneys aren’t filtering properly.

Your doctor might also recommend a 24-hour urine test. This test involves collecting all of your urine for a full day. You’ll receive a special container and instructions for how to store the sample. Once completed, the container is returned to a lab. This test helps your doctor measure how much protein is lost in your urine and how well your kidneys are functioning over time.

After confirming protein in your urine with urine protein tests, your doctor might use blood tests, imaging tests, or a kidney biopsy to learn more about your kidney health.

Treatments for Managing Swelling With Proteinuria

Treatments for proteinuria can help reduce any resulting swelling. The treatment your doctor recommends will depend on factors such as the amount of protein in your urine, your kidney function, and whether you have high blood pressure or other health conditions.

ACE Inhibitors and ARBs

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs) are two types of medications often prescribed for kidney disease. These treatments help slow damage to the glomeruli and reduce the amount of protein lost in your urine.

Although they work in slightly different ways, both types of medication reduce the effect of a hormone called angiotensin 2 (often written with Roman numerals as angiotensin II), which raises blood pressure. By relaxing blood vessels in your kidneys and elsewhere, ACE inhibitors and ARBs help lower blood pressure.

By supporting your kidney function and reducing protein in your urine, ACE inhibitors and ARBs help with swelling and other symptoms of proteinuria.

Diuretics

In some cases, doctors prescribe diuretics (also called water pills) to treat swelling related to nephrotic syndrome. Diuretics help your kidneys get rid of extra salt and water, which makes you pee more often and reduces fluid retention.

Unlike other treatments that address the root cause of kidney damage, diuretics treat swelling directly. They can also help lower high blood pressure.

Corticosteroids and Other Immune Therapies

Corticosteroids are medications that lower inflammation and calm an overactive immune system. Doctors may prescribe systemic (whole-body) or targeted-release corticosteroids for IgA nephropathy to reduce inflammation in the glomeruli and help control proteinuria.

In some cases, people with IgAN may also benefit from other immune-based therapies, such as immunosuppressive drugs that help regulate the immune system. These treatments are used when the immune system plays a key role in causing kidney damage.

Endothelin Pathway Antagonists

Endothelin receptor antagonists (ERAs) are a newer class of medication that work by blocking the endothelin pathway, which affects pressure inside the kidney’s filtering units. Also called endothelin pathway blockers, these treatments help lower protein levels in the urine and reduce the strain on the kidneys.

Complement Pathway Inhibitors

Some newer and experimental treatments work by targeting the complement system, a part of the immune system that can contribute to kidney inflammation in IgAN. By calming this overactive immune response, complement inhibitors can help prevent further kidney damage and reduce proteinuria.

Lifestyle Changes for Managing Swelling With Proteinuria

In addition to medication, lifestyle changes can help reduce swelling caused by proteinuria. Making small adjustments to your diet and daily habits can support your treatment plan and help protect your kidney health.

Eat Less Salt

Eating too much salt can cause your body to hold on to extra fluid, which can contribute to swelling. Your doctor or a registered dietitian may recommend lowering your sodium intake to help your body get rid of excess water and waste. They may also suggest reducing saturated fat and cholesterol, which can affect heart and kidney health.

You can reduce your salt intake by making a few easy changes to your cooking and eating habits:

• Choosing fresh foods over frozen, packaged, or canned
• Reading food labels to avoid high-sodium products
• Using seasonings and spices other than salt to create flavor
• Request less or no salt in restaurant meals
• Never adding extra table salt to your meal once it’s prepared

Track Your Weight

Edema related to nephrotic syndrome can come with sudden weight gain. Your doctor may ask you to track your weight daily as a way to monitor fluid retention and changes in kidney function. Rapid weight changes may signal that your swelling, or your kidney condition, is getting worse.

Can Drinking More Water Reduce Swelling?

Because edema comes from imbalances between fluid and electrolytes, you might wonder if drinking water can reduce the amount of protein in your urine and help with swelling. Drinking more water won’t stop your kidneys from leaking protein, even though it can affect the result of a protein urine test.

That said, drinking the right amount of water is important for supporting kidney function, preventing dehydration, and avoiding constipation, especially if you’re taking diuretics. Your doctor can help you figure out how much fluid is right for you based on your stage of kidney disease, swelling, and medications.

Talk to Your Doctor

Let your doctor know if you notice new or increasing swelling anywhere on your face or body, especially if you have IgA nephropathy. Your doctor or nephrologist can measure the protein in your urine and check for other symptoms to find out if nephrotic syndrome is causing the swelling. Be sure to take medications only as your doctor prescribes them and follow any other treatment recommendations closely.

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