GLOMERULAR DISEASE OVERVIEW
Glomerular disease reduces the ability of the kidneys to maintain a balance of certain substances in bloodstream. Normally, the kidneys should filter toxins out of the bloodstream and excrete them in the urine, but should keep red blood cells and protein in the bloodstream. In people with glomerular disease, red blood cells and protein may be excreted into the urine, while toxins may be retained.
Glomerular disease can occur by itself (eg, affecting only the kidney), or may be associated with an underlying medical condition that affects other organ systems, such as lupus, diabetes, or certain infections. Glomerular disease can develop suddenly (called acute), or develop slowly over a period of years (called chronic). Treatment of glomerular disease depends upon its cause and type.
NORMAL KIDNEY FUNCTION
To understand glomerular disease, it may be helpful to understand how the kidneys normally function. The kidneys are bean-shaped, approximately fist-sized organs that are located in the mid-back, just below the rib cage on each side of the body (figure 1 and figure 2).
The kidneys filter the body's blood supply with tiny structures, known as nephrons (figure 3). Each nephron is composed of a glomerulus and a tubule. The glomerulus filters wastes and excess fluids, while the tubules modify the waste to form urine. Glomerular disease affects the glomerulus, causing it to filter and excrete incorrectly.
GLOMERULAR DISEASE FEATURES
Signs and symptoms of glomerular disease depend upon the cause. The first sign of a problem may be an abnormal urine test (urinalysis) that was performed for other reasons.
●The urinalysis may show red blood cells; normally, fewer than four red blood cells should be visible per field of view when looking through a microscope at high power.
●The urine may be discolored; red blood cells in the urine can cause the urine to become a light or dark brown color (called hematuria). (See "Patient information: Blood in the urine (hematuria) in adults (Beyond the Basics)".)
●Excessive protein in the urine (called proteinuria) can be present. (See "Patient information: Protein in the urine (proteinuria) (Beyond the Basics)".)
Signs and symptoms may also include an elevated blood pressure (greater than 140/90 mmHg), fluid retention (edema) in the hands, face, feet, and/or abdomen, fatigue (due to anemia or kidney failure), or urinating infrequently. (See "Patient information: Edema (swelling) (Beyond the Basics)".)
TYPES OF GLOMERULAR DISEASE
The two basic types of glomerular disease include nephritic and nephrotic, but with some diseases, the two types can overlap. (See "Differential diagnosis and evaluation of glomerular disease".)
Nephritic — The key feature of nephritic disease is blood in the urine (hematuria). In mild disease, there may not be significant impairment of kidney function or proteinuria. In fact, a person with glomerulonephritis may not have any symptoms, and their condition may go unnoticed until blood and protein are found during a routine urinalysis.
Examples of conditions that may cause mild glomerulonephritis include:
●Mild postinfectious glomerulonephritis
●Thin basement membrane disease
●Henoch-Schönlein purpura (IgA vasculitis)
●Mesangial proliferative glomerulonephritis
Persons with severe nephritic disease have hematuria and, often, impaired kidney function. Urine testing may also show high levels of protein, and patients may have edema (swelling in the lower legs) or high blood pressure.
Examples of conditions that may cause severe glomerulonephritis include:
●Severe postinfectious glomerulonephritis
Nephrotic syndrome — People with nephrotic syndrome have protein in the urine (proteinuria) but, often, little to no blood in the urine (hematuria). Kidney function may worsen as nephrotic syndrome progresses. (See "Patient information: The nephrotic syndrome (Beyond the Basics)".)
Examples of conditions that may cause nephrotic syndrome include:
●Minimal change disease
●Focal segmental glomerulosclerosis
●Membranous nephropathy (including lupus)
●Postinfectious glomerulonephritis (later stage)
●Primary amyloidosis or the related disorder light chain deposition disease
●Benign nephrosclerosis (often due to high blood pressure)
GLOMERULAR DISEASE DIAGNOSIS
Glomerular disease is diagnosed based upon blood or urine tests. Other tests, including imaging tests and/or a kidney biopsy, may be used to help diagnose the specific type of glomerular disease.
Urine tests — The urinalysis may show red blood cells (which are seen when there is damage or inflammation in the glomeruli), white blood cells (which can indicate inflammation), or increased protein levels (which is an indicator of glomerular damage).
Blood tests — Blood tests are used to measure the level of creatinine and blood urea nitrogen (BUN), which become elevated when the kidneys are damaged and are not filtering properly. Blood tests may also be used to diagnose underlying medical conditions (such as diabetes, lupus, or certain infections).
Imaging tests — An ultrasound of the kidney is frequently recommended if glomerular disease is suspected, primarily to rule out other causes of blood in the urine and/or decreased kidney function. The ultrasound can also measure the size of the kidneys, which can provide a clue as to the duration of the kidney disease.
Kidney biopsy — A kidney (renal) biopsy may be needed to definitively determine the cause of glomerular disease in patients that cannot be diagnosed by blood tests or imaging tests alone. A separate topic review discusses renal biopsy. (See "Patient information: Renal (kidney) biopsy (Beyond the Basics)".)
GLOMERULAR DISEASE TREATMENT
The treatment of glomerular disease depends upon the form (acute or chronic), the underlying cause, and the severity of associated signs and symptoms. Some forms of glomerular disease, such as that caused by infection, improve after the infection is treated.
Other types of glomerular disease may require treatment with immune suppressant medications, such as glucocorticoids (commonly called steroids). Rapidly progressive glomerulonephritis is sometimes treated with plasmapheresis, which removes components of the blood that could be causing the inflammation. Some forms of glomerular disease do not require treatment, while others do not respond to any therapy.
Managing high blood pressure — Management of high blood pressure is important to prevent further damage to the kidneys; one or more medications may be needed. One or more high blood pressure medications may be recommended for patients with chronic glomerular disease to decrease the amount of protein in the urine and slow the rate of progression of kidney disease. (See "Patient information: High blood pressure treatment in adults (Beyond the Basics)" and "Patient information: High blood pressure, diet, and weight (Beyond the Basics)".)
GLOMERULAR DISEASE COMPLICATIONS
Some types of glomerular disease are associated with complications, including high blood pressure, acute or chronic kidney failure, and nephrotic syndrome. (See "Patient information: The nephrotic syndrome (Beyond the Basics)".)
High blood pressure — High blood pressure can develop in people with glomerular disease due to kidney damage and build up of waste products and excess fluid in the bloodstream. One or more medications may be needed to reduce blood pressure and prevent further damage to the kidneys. (See "Patient information: High blood pressure treatment in adults (Beyond the Basics)".)
Acute kidney failure — Sudden onset (acute) kidney failure is more likely to occur with acute glomerulonephritis (eg, diffuse nephritic). If the glomeruli are unable to filter the blood adequately, waste products and excess fluids build up in the bloodstream quickly. Hemodialysis may be needed to remove waste products and excess fluids. This could be temporary, until the kidney function recovers, or may be long term if the kidneys become damaged. (See "Patient information: Hemodialysis (Beyond the Basics)".)
Chronic kidney failure — If kidney function continues to worsen, dialysis or kidney transplantation may be needed to perform the normal functions of the kidneys. There are two types of dialysis: hemodialysis and peritoneal dialysis. (See "Patient information: Hemodialysis (Beyond the Basics)" and "Patient information: Peritoneal dialysis (Beyond the Basics)".)
WHERE TO GET MORE INFORMATION
Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient information: Chronic kidney disease (The Basics)
Patient information: Glomerular disease (The Basics)
Patient information: Cadmium toxicity (Cadmium poisoning) (The Basics)
Patient information: Paget disease of bone (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient information: Blood in the urine (hematuria) in adults (Beyond the Basics)
Patient information: Protein in the urine (proteinuria) (Beyond the Basics)
Patient information: Edema (swelling) (Beyond the Basics)
Patient information: The nephrotic syndrome (Beyond the Basics)
Patient information: Renal (kidney) biopsy (Beyond the Basics)
Patient information: High blood pressure treatment in adults (Beyond the Basics)
Patient information: High blood pressure, diet, and weight (Beyond the Basics)
Patient information: Hemodialysis (Beyond the Basics)
Patient information: Peritoneal dialysis (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Diagnostic approach to the patient with acute kidney injury (acute renal failure) or chronic kidney disease
Differential diagnosis and evaluation of glomerular disease
Etiology and evaluation of hematuria in adults
Assessment of urinary protein excretion and evaluation of isolated non-nephrotic proteinuria in adults
Mechanisms of immune injury of the glomerulus
The following organizations also provide reliable health information.
●National Library of Medicine
●National Institute of Diabetes and Digestive and Kidney Diseases
●National Kidney Foundation
●American Kidney Fund
●American Association of Kidney Patients