Nephrotic Syndrome Symptoms: Swelling, Foamy Urine & Diagnosis

Quick Glance: Common Nephrotic Syndrome Symptoms

Nephrotic syndrome usually develops slowly, but may occur suddenly in some people. Early identification of these symptoms helps avoid kidney problems. Below is an overview of some common symptoms of nephrotic syndrome:

Puffiness around the eyes, especially in the morning
Swelling of the feet, ankles or legs
Swelling of the hands, face or abdomen
Foamy or frothy urine
Rapid weight gain caused by fluid retention
Tiredness or low energy
Reduced appetite
Clothes, shoes or rings feel tighter because of swelling

Nephrotic Syndrome Symptoms That Should Not Be Ignored

Nephrotic syndrome increases the risk of blood clots, infections, hypertension and kidney problems. New or worsening warning signs require medical assessment.

Some warning signs of nephrotic syndrome that should not be ignored are shown in the table below:

Symptom	What It May Indicate
Rapidly increasing swelling of the face, legs or abdomen	Significant fluid retention or worsening nephrotic syndrome
Persistent foamy urine	A large amount of protein in the urine, although testing is required to confirm the cause
Rapid weight gain over a short period	Increasing accumulation of fluid
Breathlessness, particularly when resting or lying down	Fluid around or within the lungs, or another heart or lung complication
Markedly reduced urine output	Acute kidney injury, reduced kidney function or severe fluid imbalance
Fever, chills or severe abdominal pain	A potentially serious infection
Pain, redness, warmth or swelling in one leg	Possible deep vein thrombosis
Severe headache or vision changes with very high blood pressure	Possible hypertensive emergency
Blood in the urine	An underlying glomerular disorder or another urinary condition requiring evaluation

Why Do Nephrotic Syndrome Symptoms Occur?

Nephrotic syndrome symptoms develop when the glomeruli, the kidney’s tiny filtering units, allow too much protein, especially albumin, to leak into the urine. Low albumin levels make it easier for fluid to move from the bloodstream into surrounding tissues, causing swelling around the eyes, legs, feet and abdomen.

The kidneys may also retain extra sodium and water, which worsens swelling and causes rapid weight gain. Protein loss can also contribute to foamy urine, tiredness, increased cholesterol levels and a higher risk of infections and blood clots.

Nephrotic Syndrome Symptoms That Require Immediate Medical Attention

If you have any of the following symptoms, it is recommended to get a medical evaluation to prevent progression of nephrotic syndrome and avoid complications:

Rapidly worsening or widespread swelling
Very little urine
Fever, chills or signs of infection
Severe abdominal pain
A severe headache with vision changes
Persistently high blood pressure
Blood in the urine

Symptoms of Nephrotic Syndrome Based on Type

Primary and secondary nephrotic syndrome generally cause the same core symptoms. The main difference is whether the damage begins in the kidneys or results from a condition affecting other parts of the body.

The table below summarises symptoms of nephrotic syndrome based on its type:

Type of Nephrotic Syndrome	Common Symptoms and Signs
Primary Nephrotic Syndrome	Puffiness around the eyes, swelling of the feet, ankles, legs or abdomen, foamy urine, fluid-related weight gain, tiredness and reduced appetite
Secondary Nephrotic Syndrome	Swelling in the ankles, legs, feet or abdomen, foamy urine, weight gain and tiredness, together with possible symptoms of the underlying condition, such as diabetes, lupus, infection or another systemic disease

Symptoms of Nephrotic Syndrome-Specific Condition

The symptoms of most diseases causing nephrotic syndrome overlap. However, congenital nephrotic syndrome has a more recognisable age-related presentation, as it begins during infancy. These symptoms include:

Nephrotic Syndrome-Specific Condition	Common Symptoms and Findings
Congenital Nephrotic Syndrome	Generalised swelling beginning during the first months of life, abdominal swelling, poor feeding, low birth weight, poor growth, reduced urine output, recurrent infections and signs of malnutrition

Symptoms of Nephrotic Syndrome in Children

The symptoms of nephrotic syndrome among children vary from those of adults. Puffiness around the eyes is usually the first sign.

The various symptoms of nephrotic syndrome include:

Eye puffiness, especially in the morning
Foot, ankle, abdomen or leg swelling
Foamy urine
Rapid weight gain due to fluid retention
Abdominal swelling
Nausea
Muscle cramps
Diarrhoea
Poor appetite
Fatigue or irritability
Frequent infections

Can You Have Nephrotic Syndrome Without Symptoms?

Yes. Some people may have very few noticeable symptoms when nephrotic syndrome is first detected. A routine urine test may identify substantial protein loss before obvious swelling develops.

However, mild proteinuria alone cannot be used to diagnose nephrotic syndrome. The diagnosis is based on significant protein loss in the urine together with findings, such as low blood albumin, swelling and high blood lipid levels.

Symptoms of nephrotic syndrome generally become more noticeable as fluid retention increases. But symptom severity does not always reflect how much kidney damage is present.

When Can Nephrotic Syndrome Symptoms Become Life-Threatening?

Nephrotic syndrome is usually not an emergency, but it can lead to serious complications involving blood clots, infection, fluid balance, blood pressure and kidney function.

Some of the serious complications of nephrotic syndrome are listed below:

Serious Complication	What Can Happen
Pulmonary Embolism	A blood clot travels to the lungs, causing sudden breathlessness, chest pain, rapid heartbeat or coughing up blood
Deep Vein Thrombosis	A clot forms in a deep vein, usually causing pain, warmth, redness and swelling in one leg
Severe Infection or Sepsis	Loss of protective proteins and other factors may increase susceptibility to infection, which can spread through the bloodstream
Acute Kidney Injury	Kidney function declines suddenly, causing very little urine, fluid imbalance and abnormal electrolyte levels
Severe Fluid Overload	Fluid accumulates around or within the lungs, causing breathing difficulty and low oxygen levels
Hypertensive Emergency	Severely raised blood pressure damages the brain, heart, kidneys or eyes and may cause headache, visual changes, confusion or seizures
Kidney Failure	Severe or progressive underlying kidney disease may lead to long-term loss of kidney function

How are Nephrotic Syndrome Symptoms Diagnosed?

Nephrotic syndrome is diagnosed by combining symptoms and findings of physical examinations with urine and blood tests. Further investigations may help identify the kidney disease or systemic condition responsible for the syndrome.

An overview of these tests and their purpose to diagnose nephrotic syndrome is given below:

Diagnostic Test or Assessment	Purpose
Medical History and Physical Examination	Identifies symptoms, complications and possible underlying causes
Urine Dipstick Test	Provides a rapid initial screen for proteinuria
Urine Protein-to-Creatinine or Albumin-to-Creatinine Ratio	Estimates the amount of protein being lost
Twenty-Four-Hour Urine Collection	Quantifies protein loss when a more detailed measurement is required
Blood Albumin and Total Protein	Detects reduced blood protein caused by urinary loss
Kidney Function and Electrolyte Tests	Assesses kidney function and possible complications
Lipid Profile	Detects the high blood lipid levels commonly associated with nephrotic syndrome
Urinalysis and Urine Microscopy	Helps identify the pattern of kidney damage
Tests for An Underlying Cause	Looks for diabetes, lupus, infection or another secondary cause
Kidney Ultrasound	Assesses kidney anatomy and may guide further investigation
Kidney Biopsy	Identifies the specific kidney disease when the cause is uncertain
Genetic testing	May be used in congenital, infantile, familial or selected treatment-resistant cases

FAQs

Q1. What is the first symptom of nephrotic syndrome?

Ans: Puffiness around the eyes, especially in the morning, is often the first noticeable symptom of nephrotic syndrome.
Q2. Can nephrotic syndrome develop without symptoms?

Ans: Yes. Nephrotic syndrome in its early stages may be detected through urine and blood tests before noticeable swelling develops.
Q3. Does foamy urine always mean nephrotic syndrome?

Ans: No. Foamy urine has several possible causes other than nephrotic syndrome. Therefore, persistent foaminess should be assessed for protein in the urine.
Q4. Can nephrotic syndrome cause weight gain?

Ans: Yes. Rapid weight gain may occur when excess fluid accumulates in the body due to nephrotic syndrome.
Q5. Are nephrotic syndrome symptoms different in children?

Ans: Children with nephrotic syndrome often first develop puffiness around the eyes, followed by swelling elsewhere, foamy urine, tiredness and reduced appetite.
Q6. When should I see a doctor for nephrotic syndrome?

Ans: When you experience swelling, foamy urine, weight gain and decreased urination, you should seek medical care.
Q7. Are nephrotic syndrome symptoms different in men and women?

Ans: No. The core symptoms of nephrotic syndrome are generally the same and depend more on the underlying cause than on gender.
Q8. Which nephrotic syndrome symptoms indicate a medical emergency?

Ans: Nephrotic syndrome symptoms,, like sudden breathlessness, chest pain, coughing up blood, one-sided leg swelling, no urine, confusion, seizures or loss of consciousness require emergency care.

References
- https://www.merckmanuals.com/professional/nephrology/glomerular-disorders/overview-of-nephrotic-syndrome?autoredirectid=37479&mredirectid=133
- https://www.mayoclinic.org/diseases-conditions/nephrotic-syndrome/symptoms-causes/syc-20375608
- https://my.clevelandclinic.org/health/diseases/5989-nephrotic-syndrome
- https://www.niddk.nih.gov/health-information/kidney-disease/nephrotic-syndrome-adults
- https://www.kidney.org/kidney-topics/nephrotic-syndrome
- https://pharmaceutical-journal.com/article/ld/nephrotic-syndrome-in-adults-symptoms-and-management