Nephrotic Syndrome: Symptoms, Causes, and Treatment Guide
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
TL;DR: Nephrotic syndrome is a kidney disorder in which the kidney's tiny filters (glomeruli) are damaged and let too much protein — mainly albumin — leak into the urine. It typically causes severe swelling around the eyes, ankles, and feet, foamy urine, weight gain from fluid retention, fatigue, and loss of appetite. It is usually caused by a condition that damages the glomeruli, such as diabetic kidney disease, minimal change disease (the most common cause in children), focal segmental glomerulosclerosis, membranous nephropathy, lupus, or amyloidosis. Diagnosis involves urine tests, blood tests, and sometimes a kidney biopsy. Treatment targets the underlying cause and usually combines blood pressure medicines (ACE inhibitors or ARBs), diuretics, statins, blood thinners, and immune-suppressing drugs, along with diet changes such as less salt and less fluid. This guide covers every symptom, cause, complication, and treatment option in plain language.
Quick Answer
What is nephrotic syndrome? Nephrotic syndrome is a kidney disorder in which damaged kidney filters allow too much protein to pass into the urine, causing swelling (especially in the feet, ankles, and around the eyes) and raising the risk of blood clots, infections, and kidney damage.
Nephrotic syndrome means a kidney disorder that causes the body to pass too much protein in urine.
The main symptoms are severe swelling (edema) around the eyes and in the ankles and feet, foamy urine, weight gain from fluid retention, fatigue, and loss of appetite.
It usually starts with damage to the glomeruli — the clusters of tiny blood vessels in the kidneys that filter the blood.
The six recognized causes include diabetic kidney disease, minimal change disease (most common in children), focal segmental glomerulosclerosis, membranous nephropathy, lupus, and amyloidosis.
Doctors diagnose it with urine tests, blood tests, and sometimes a kidney biopsy.
Treatment targets the underlying condition and typically combines blood pressure medicines, water pills (diuretics), statins, blood thinners, and immune-suppressing medications, plus diet changes.
It can raise the risk of blood clots, high cholesterol, poor nutrition, high blood pressure, kidney injury, chronic kidney disease, and infections.
What Is Nephrotic Syndrome?
The kidneys remove waste and excess fluid from the blood through filtering units called nephrons. Each nephron contains a filter called a glomerulus — a network of tiny blood vessels called capillaries.
When blood flows into a glomerulus, tiny molecules — water, essential minerals and nutrients, and wastes — pass through the capillary walls. Large molecules, such as proteins and red blood cells, do not.
Plain-language definition: Nephrotic syndrome is a kidney disorder in which the kidneys' filters get damaged and let too much protein leak from the blood into the urine. The protein loss causes fluid to build up in the body, producing swelling.
In nephrotic syndrome, the glomeruli are damaged. Damaged glomeruli allow too much blood protein — mainly albumin — to leave the body through the urine. Albumin is needed to maintain the right amount of fluid in the body, so losing it leads to fluid retention and swelling, particularly in the feet and ankles.
What Are the Symptoms of Nephrotic Syndrome?
The signs and symptoms of nephrotic syndrome can affect how you look and feel. The five main symptoms are listed below with plain-language descriptions.
Symptom | What it involves |
Severe swelling (edema) | Swelling, particularly around the eyes and in the ankles and feet |
Foamy urine | A result of excess protein in the urine |
Weight gain | Caused by fluid retention |
Fatigue | Feeling unusually tired |
Loss of appetite | Reduced desire to eat |
Swelling (edema) is often the most noticeable sign. Because the body is losing albumin — the protein that keeps the right amount of fluid in the bloodstream — fluid leaks into surrounding tissues and collects in the feet, ankles, and face.
When Should You See a Doctor?
The guidance for nephrotic syndrome is straightforward: make an appointment with your doctor if you have any signs or symptoms that worry you.
Persistent swelling around the eyes, swollen ankles and feet, or urine that looks consistently foamy all deserve an evaluation — especially because the condition can quietly raise the risk of blood clots, high cholesterol, and kidney damage.
What Causes Nephrotic Syndrome?
Nephrotic syndrome is usually caused by damage to the glomeruli — the clusters of tiny blood vessels in the kidneys that filter the blood.
Healthy glomeruli keep blood protein (mainly albumin) from seeping into the urine. When they are damaged, too much blood protein leaves the body, leading to nephrotic syndrome.
The Six Recognized Causes
Many diseases and conditions can damage the glomeruli and lead to nephrotic syndrome. The table below summarizes each cause and how it works.
Cause | How it damages the filters |
Diabetic kidney disease | Diabetes leads to kidney damage (diabetic nephropathy) that affects the glomeruli |
Minimal change disease | Abnormal kidney function, but kidney tissue looks normal or nearly normal under a microscope; most common cause in children |
Focal segmental glomerulosclerosis | Scarring of some of the glomeruli; can result from another disease, a genetic defect, certain medications, or no known reason |
Membranous nephropathy | Thickening of membranes within the glomeruli from immune-system deposits; can be linked to lupus, hepatitis B, malaria, or cancer |
Systemic lupus erythematosus (lupus) | A chronic inflammatory disease that can cause serious kidney damage |
Amyloidosis | Amyloid proteins accumulate in organs and often damage the kidneys' filtering system |
For some causes, such as minimal change disease, the reason for the abnormal function typically cannot be determined.
What Are the Risk Factors for Nephrotic Syndrome?
Factors that can increase your risk of nephrotic syndrome fall into three groups.
Risk factor | Details |
Medical conditions that can damage the kidneys | Diabetes, lupus, amyloidosis, reflux nephropathy, and other kidney diseases |
Certain medications | Nonsteroidal anti-inflammatory drugs (NSAIDs) and drugs used to fight infections |
Certain infections | HIV, hepatitis B, hepatitis C, and malaria |
What Complications Can Nephrotic Syndrome Cause?
Nephrotic syndrome increases the risk of several other health problems. Doctors may recommend medications and dietary changes to help prevent these complications.
Complication | Why it happens |
Blood clots | Damaged glomeruli lose blood proteins that help prevent clotting, raising the risk of a clot in the veins |
High blood cholesterol and triglycerides | When blood albumin falls, the liver makes more albumin and also releases more cholesterol and triglycerides |
Poor nutrition | Losing too much blood protein can cause malnutrition and weight loss (masked by edema), along with anemia, low blood protein, and low vitamin D |
High blood pressure | Glomerular damage and excess fluid buildup can raise blood pressure |
Acute kidney injury | If the kidneys lose the ability to filter blood, waste builds up quickly and emergency dialysis may be needed |
Chronic kidney disease | Kidneys can lose function over time, possibly requiring dialysis or a kidney transplant |
Infections | People with nephrotic syndrome have an increased risk of infections |
Dialysis explained. Dialysis is an artificial means of removing extra fluids and waste from the blood, typically using a machine called a dialyzer. A kidney transplant replaces the function of failed kidneys.
How Is Nephrotic Syndrome Diagnosed?
Diagnosis involves a small set of urine, blood, and tissue tests that together show how much protein is leaking and what is damaging the filters.
Diagnostic step | What happens |
Urine tests | A urinalysis can reveal abnormalities such as large amounts of protein; you might be asked to collect urine over 24 hours |
Blood tests | Low albumin and often decreased overall blood protein; increased cholesterol and triglycerides often accompany albumin loss; creatinine and urea nitrogen levels assess overall kidney function |
Kidney biopsy | A needle is inserted through the skin and into the kidney to remove a small tissue sample, which is sent to a lab for testing |
Creatinine and urea nitrogen explained. These are waste products normally filtered by the kidneys. When they build up in the blood, it signals that the kidneys are not filtering well.
How Is Nephrotic Syndrome Treated?
Treatment involves two parts: treating the medical condition that is causing the nephrotic syndrome, and using medications and diet changes to control signs, symptoms, and complications.
Medications Used in Treatment
Medication class | How it helps | Examples |
Blood pressure medications | ACE inhibitors reduce blood pressure and the amount of protein released in urine; ARBs work similarly | ACE inhibitors: lisinopril, benazepril, captopril, enalapril. ARBs: losartan, valsartan |
Water pills (diuretics) | Control swelling by increasing the kidneys' fluid output | Furosemide, spironolactone, thiazides (hydrochlorothiazide, metolazone) |
Cholesterol-reducing medications | Statins can lower cholesterol; it is not clear whether they improve outcomes such as avoiding heart attacks | Atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin, simvastatin |
Blood thinners (anticoagulants) | Decrease the blood's ability to clot, especially if a blood clot has occurred | Heparin, warfarin, dabigatran, apixaban, rivaroxaban |
Immune system-suppressing medications | Control the immune system; corticosteroids can decrease the inflammation that accompanies some causes | Rituximab, cyclosporine, cyclophosphamide |
ACE inhibitors and ARBs are generally used first for blood pressure and protein control. Renin inhibitors may also be used in some cases.
What Diet Changes Help? (Self-Care)
Changes to your diet might help with nephrotic syndrome. Your doctor might refer you to a dietitian, an expert in nutrition, who might recommend the following steps.
Step | How to do it |
Choose lean protein | Plant-based protein is helpful in kidney disease |
Reduce fat and cholesterol | Helps control blood cholesterol levels |
Eat a low-salt diet | Helps control swelling |
Reduce liquids | Reduce the amount of liquid in your diet |
Preparing for Your Appointment
Start by seeing your primary care doctor. If a kidney problem such as nephrotic syndrome is suspected, you may be referred to a nephrologist — a doctor who specializes in the kidneys.
When you make the appointment, ask if there is anything you need to do in advance, such as restricting your diet. Take a family member or friend along, if possible, to help you remember the information you are given.
Make a list of your symptoms and when they began, key personal information (including major stresses or recent life changes), all medications, vitamins, and supplements with doses, and questions to ask.
Questions to ask your doctor | What your doctor may ask you |
What's the most likely cause of my (or my child's) nephrotic syndrome? | Do symptoms come and go, or are they constant? |
What tests do I (or my child) need? | How severe are the symptoms? |
Is this condition likely temporary? | Does anything seem to improve the symptoms? |
What are the treatment options, and which do you recommend? | What appears to worsen the symptoms? |
Are there diet changes I can make, and could a dietitian help? | — |
How can I best manage this with my (or my child's) other conditions? | — |
Conclusion
Nephrotic syndrome is a kidney disorder in which damaged filters let too much protein escape into the urine, producing swelling, foamy urine, and fluid weight gain while raising the risk of clots, infections, and kidney damage. Treatment works best when it targets the underlying cause — from diabetic kidney disease to minimal change disease — supported by blood pressure medicines, diuretics, and diet changes.
Talk to a doctor promptly if you notice persistent swelling around the eyes, ankles, or feet, or urine that is consistently foamy. Early evaluation makes every treatment option more effective.
Frequently Asked Questions
Is nephrotic syndrome curable?
Treatment controls the condition and its complications by targeting the cause and reducing protein loss and swelling. Whether it resolves depends on the underlying disease; some causes, such as minimal change disease, are often more responsive to treatment than others.
What are the first signs of nephrotic syndrome?
Severe swelling (edema), particularly around the eyes and in the ankles and feet, is usually the most noticeable early sign, along with foamy urine, weight gain from fluid retention, fatigue, and loss of appetite.
Why is my urine foamy?
Foamy urine is a result of excess protein in the urine. In nephrotic syndrome, damaged kidney filters let protein (mainly albumin) leak into the urine, which makes it look foamy.
What is the difference between albumin and protein in this condition?
Albumin is the main blood protein that maintains the right amount of fluid in the body. Nephrotic syndrome specifically causes albumin to leak into the urine, and overall blood protein often falls along with it.
What is the most common cause in children?
Minimal change disease is the most common cause of nephrotic syndrome in children. It causes abnormal kidney function even though kidney tissue looks normal or nearly normal under a microscope.
What tests diagnose nephrotic syndrome?
Urine tests (urinalysis, sometimes a 24-hour urine collection) show large amounts of protein; blood tests show low albumin, increased cholesterol and triglycerides, and creatinine and urea nitrogen levels that reflect kidney function; a kidney biopsy may identify the specific cause.
What medications treat nephrotic syndrome?
The main options are blood pressure medications (ACE inhibitors and ARBs), water pills (diuretics) to control swelling, statins for cholesterol, blood thinners if a clot has occurred, and immune system-suppressing medications such as corticosteroids, rituximab, cyclosporine, and cyclophosphamide.
What diet changes help?
A dietitian may recommend choosing lean and plant-based protein, reducing fat and cholesterol, eating a low-salt diet to control swelling, and reducing liquid intake.
References
Nephrotic syndrome — Symptoms and causes (Feb. 23, 2022)
Nephrotic syndrome — Diagnosis and treatment (Feb. 23, 2022)
This article is based on the two referenced sources, last updated Feb. 23, 2022. This content is for general information only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your individual health.
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