INTRODUCTION
Nephritic syndrome is characterized by glomerular damage leading to hematuria, pyuria, water retention, and subsequent hypertension and edema. It can be caused by a variety of conditions including autoimmune, hereditary, and infectious diseases. This article provides an overview of nephritic syndrome; Nephritic diseases can present in varying degrees of severity, ranging from asymptomatic hematuria to systemic involvement as in rapidly progressive glomerulonephritis. The urine sediment is typically characterized by red blood cell (RBC) casts, mild to moderate proteinuria (< 3.5 g/day), and sterile pyuria. Diagnosis of the underlying disease is often based on presentation and laboratory values, although renal biopsy may be indicated for confirmation.
Nephritic syndrome is not a disease but a syndrome. A syndrome is a group of symptoms that often and predictably occur together, and which develop as a result of another condition. Syndromes are not necessarily specific to any disease or disorder. Nephritic syndrome has many potential triggers, therefore, successfully treating it involves identifying the underlying causes.
Nephritic syndrome has both acute and chronic forms. Acute, or rapidly-progressing, nephritic syndrome usually comes on suddenly and, because of acute and painful symptoms, seldom goes undetected. Chronic nephritic syndrome typically progresses slowly and often goes undetected for some time.
Chronic inflammation of the kidneys can cause scarring, which may negatively impact kidney function and lead to high blood pressure and, eventually, if left undiagnosed and untreated, to a need for dialysis (renal replacement therapy, when a dialysis machine replaces the kidneys’ function and filters waste products from the blood), and possibly kidney transplantation.

CAUSES-
Nephritic syndrome is the result of inflammation affecting small groups of blood vessels, known as glomeruli, in the kidneys. As the glomeruli are the kidneys’ main filter units, this inflammation disrupts the kidneys’ ability to adequately filter blood. The inflammation can originate in the kidneys themselves or be the result of infection or injury elsewhere in the body.
It can occur in people of any age, including children.
Nephritic syndrome can develop as a result of any of the following:
Primary glomerular diseases: Such as IgA nephropathy (Berger’s disease) or membranoproliferative glomerulonephritis. IgA nephropathy is a very common cause of nephritic syndrome.
Bacterial infections: Such as methicillin-resistant staphylococcus aureus (MRSA), pneumococcal pneumonia, typhoid, infective endocarditis, or secondary syphilis. Nephritic syndrome following a streptococcal throat infection is fairly common, especially in children.
Viral infections: Such as hepatitis B, mumps, measles, chickenpox or glandular fever (mononucleosis).
Multisystem systemic/inflammatory diseases: Such as vasculitis, Goodpasture’s Syndrome, granulomatosis with polyangiitis, Henoch-Schönlein purpura, or lupus (systemic lupus erythematosus).

| Associations | Findings | Treatment | ||
|---|---|---|---|---|
| Poststreptococcal glomerulonephritis | Occurs weeks after group A β-hemolytic streptococci infections Pharyngitis/tonsillitis (most common): 1–2 weeks Skin infections: 3–4 weeks Usually affects children between the ages of 3–12 years Can lead to RPGN in some cases | Positive antistreptococcal antibodies (ASO, ADB) ↓ Serum C3 complement levels Tea- or cola-colored urine LM: glomeruli appear enlarged and hypercellular IM: granular subepithelial immune complex depositions (IgG, IgM, C3) → “lumpy-bumpy” appearance EM: dome-shaped, subepithelial deposits (“humps”) | Usually self-limiting Supportive therapy (see “Treatment” below) | |
| IgA nephropathy (Berger’s disease) | Most common idiopathic glomerulonephritis worldwide Episodic gross hematuria during or directly after upper respiratory tract (URT), gastrointestinal (GI) infections, or strenuous exercise Occurrence: ♂ > ♀ Peak incidence: 2nd to 3rd decade of life ∼ 25-30% of the patients progress to end-stage renal disease (ESRD) within 20–25 years | Asymptomatic microhematuria with intermittent gross hematuria ↑ Serum IgA Normal C3 complement levels LM: mesangial proliferation IM: mesangial IgA deposits EM: mesangial immune complex deposits | Supportive therapy (see “Treatment” below) Glucocorticoids in severe cases | |
| Small vessel vasculitis | Granulomatosis with polyangiitis (Wegener’s) | Pulmonary and nasopharyngeal involvement is common → hemoptysis, nasal ulcers | c-ANCA Renal biopsy: segmental necrotizing glomerulonephritis EM: immune complex depositions | Supportive therapy (see “Treatment” below) Immunosuppressive therapy |
| Microscopic polyangiitis | Usually only mild respiratory symptoms | p-ANCA | ||
| Churg-Strauss syndrome | Patients present with: Asthma Allergic rhinitis Purpura Peripheral neuropathy | p-ANCA (∼ 50% of cases) Peripheral eosinophilia Focal segmental necrotizing glomerulonephritis | ||
| Goodpasture syndrome (Anti–GBM antibody disease) | Two peaks of occurrence: 3rd decade of life (♂ > ♀) and ≥ 60 years of age (♀ > ♂) Caused by antibodies against type IV collagen Antibodies can cross-react with basement membrane of pulmonary capillaries and lead to pulmonary hemorrhage and hemoptysis Can lead to RPGN | Pulmonary infiltrates on chest x–ray IM: linear deposition of immunoglobulin (IgG) along the glomerular basement membrane | Immunosuppressive therapy Plasmapheresis | |
| Thin basement membrane disease | Hereditary disorder Abnormalities of type IV collagen Good prognosis | Persistent microhematuria Possible episodic gross hematuria, typically occurring during or directly after an upper respiratory tract infection or exercise EM: diffuse thinning of glomerular basement membrane | Renal function monitoring Supportive therapy (see “Treatment” below) | |
| Alport syndrome | X-linked (usually affects males) Mutation in gene for type IV collagen Often leads to ESRD | Persistent microhematuria with intermittent gross hematuria Associated with sensorineural hearing loss and abnormalities of the eye EM: splitting and alternating thickening and thinning of the glomerular basement membrane | Supportive therapy (see “Treatment” below) Renal transplant can lead to development of Goodpasture syndrome | |
| Lupus nephritis | Complication of systemic lupus erythematosus Can be nephritic or nephrotic Can lead to RPGN in some cases | ANA, anti-dsDNA antibodies Histologic changes are very variable | Supportive therapy (see “Treatment” below) Immunosuppressive therapy | |
| Rapidly progressive glomerulonephritis (RPGN) | Glomerular diseases that progress to ESRD within weeks to months | Can be caused by a variety of diseases: Goodpasture syndrome (anti-GBM disease) Poststreptococcal glomerulonephritis Systemic lupus erythematosus (SLE) Microscopic polyangiitis Granulomatosis with polyangiitis (Wegener’s) LM, IM, EM: crescent formation, monocytes, macrophages | Immunosuppressive therapy Plasmapheresis | |
PATHOPHYSIOLOGY-
- Inflammation → cytokine release → glomerular capillary damage
- Porous glomerular basement membrane → leakage of proteins and RBCs → nephritic sediment (all blood components are detectable on urinalysis)
- Proteinuria (< 3.5 g/24h): leakage of proteins
- Hematuria: leakage of RBCs, which stick together and form red blood cell casts in the renal tubules
- Oliguria: inflammatory infiltrates reduce fluid movement across the membrane (↓ GFR)
- Azotemia: inflammation prevents sufficient filtering and excretion of urea
- Salt retention → intravascular volume expansion → hypertension and edema
- Porous glomerular basement membrane → leakage of proteins and RBCs → nephritic sediment (all blood components are detectable on urinalysis)
SYMPTOM-
Typical symptoms include passing less urine than normal, having blood in the urine and swelling of the feet or face (edema). Other possible symptoms are flank pain, back pain, headache, shortness of breath and symptoms related to the underlying cause, for example a skin rash and joint pain.
The symptoms of nephritic syndrome differ, depending on whether the acute or chronic form of the syndrome is present.
Symptoms of acute nephritic syndrome include:
- Edema in the face and legs: Edema is the accumulation of fluids in the body, usually under the skin, leading to a puffy appearance.
- Low urine volume: Known as oliguria, this is defined as less than 500ml of urine being produced in a 24-hour period.
- Hematuria: Blood in the urine which often, but not necessarily, leads to red discoloration. There are two types of hematuria: microhematuria, which indicates unseen blood, and macrohematuria, in which the blood is visible to the eye.
- High blood pressure: Hypertension, which results from the disruption of kidney function, may also occur. High blood pressure is generally defined as a resting blood pressure of 140/90 mmHg or higher in adults,
. In children, what constitutes hypertension depends on the age and size of the child. Fever, weakness and fatigue
- Appetite loss, vomiting and abdominal pain
- Malaise (a feeling of general unwellness) and nausea may also be present.
Chronic nephritic syndrome usually presents with fairly mild or even undetectable symptoms, which can include:
- Edema
- Hypertension/high blood pressure
- Kidney failure in later stages
Symptoms of kidney failure can include:
- Edema
- Hypertension/high blood pressure
- Kidney failure in later stages

Symptoms of kidney failure can include:
- Itchy skin and/or rash
- Decreased appetite
- Nausea
- Vomiting
- Fatigue
- Difficulty breathing
In both chronic and acute nephritic syndrome, the urine will usually contain high concentrations of red blood cells, as the blood cells leak out of the damaged glomeruli.
DIAGNOSIS-
The diagnosis of nephritic syndrome is typically based on a physical examination of the person and analysis of their urine (urinalysis). People with nephritic syndrome tend to have high blood pressure, so a doctor will check this. A doctor will also look for signs of:
- Abnormalities, such as dark color or cloudiness in the urine
- Protein in the urine (proteinuria), which may indicate nephrotic syndrome
- Uremia, an excess of urea or creatinine in the blood, or azotemia, an excess of nitrogen-rich waste compounds in the blood
- Increased fluid volume in the body, which may lead to edema
- Reduced filtration in the kidneys, specifically the glomeruli
A kidney biopsy (tissue sample from the kidney) may be performed to investigate the cause of the nephritic syndrome.
Urinalysis, blood tests and diagnostic procedures
Because nephritic syndrome is a cluster of symptoms rather than a disease in itself, much of the testing that makes up the diagnosis is aimed at determining what the underlying cause is. Another important element in diagnosis is differential diagnosis, as the illness may be nephrosis rather than nephritis.
In examining a person with potential nephritic syndrome, a doctor might carry out the following tests:
Take patient history: A doctor will ask the affected person about the time at which their symptoms began and attempt to determine the point at which the kidneys began to excrete protein into the urine.
Check appearance and colour of urine: Urine that is dark in colour may be very concentrated and contain blood.
Blood pressure: Hypertension can be a sign of disrupted kidney function.
Edema assessment: Edema, or fluid gathering in the tissues, can be a sign that there is not enough protein in the blood and may suggest proteinuria.
Urine dipstick test: A simple form of urinalysis that is used as a quick test for blood and protein in the urine. They will use a dipstick test, in which a test-strip of paper is immersed in a urine sample, to check for blood and protein in the urine
Urinalysis: A urine sample will be sent to a laboratory to do a precise check for protein levels and red blood cells.
Blood tests: To check levels of electrolytes, creatinine, blood urea nitrogen, immunoglobulins, antibodies, and other substances.
Kidney biopsy: This relatively straightforward procedure may be performed as an outpatient procedure or after hospital admission, depending on the patient’s particular circumstances. It uses only local anesthetic and is done using ultrasound and specialized biopsy needles to remove a small sample of tissue. Kidney biopsies are a very reliable way of distinguishing chronic glomerulonephritis from other, similar, disorders.

TREATMENT–
Treatment depends on the underlying causes. Medications (such as ramipril, benazepril, candesartan, or valsartan) are typically used to treat the high blood pressure. Medications will also be administered to reduce inflammation in the kidneys.
Generally, doctors will recommend:
- Bed rest
- A diet that is restricted in salt, potassium and fluid
- Medication to control blood pressure, if necessary
- Medication to reduce inflammation
- Medication to remove fluids from the body
- Dialysis to replace kidney function in severe cases
The time it takes to recover from nephritic syndrome varies according to its severity and the underlying cause. Most patients begin to feel better fairly soon, especially if treatment is prompt.



























