Definition & Overview
The kidneys are responsible for removing waste products from the blood and ensuring that a balance of nutrients, water, and salt is maintained. Nephrotic syndrome is a kidney disorder that upsets that balance. The kidneys clean blood through filters called nephrons. When a person has nephrotic syndrome, the nephrons are damaged, which is why even proteins are removed from the body along with the waste products.
Albumin controls blood volume, while globulin consists of antibody proteins that help the body fight off infections. Due to nephrotic syndrome, these two important proteins are excreted from the body, causing different symptoms. The condition also leads to serious complications, such as acute kidney failure, chronic kidney disease, and congestive heart failure.
Cause of Condition
Nephrotic syndrome can affect anybody of any age. When the disorder is present in children, the common cause is Minimal Change Disease (MCD), also referred to as Nil Lesions or Nil Disease. MCD is characterized by damaged glomeruli – the tiny blood vessels inside the nephron.
In adults, the most common cause of nephrotic syndrome is Focal Segmental Glomerulosclerosis (FSGS) and Membranous glomerulonephritis (MGN). FSGS is described as scarring in the kidney, while MGN is a disease that slowly progresses in the kidney.
Other than FSGS and MGN, nephrotic syndrome can also be caused by immune disorders, infections, certain medications, genetic disorders, cancer, diabetes, multiple myeloma, amyloidosis, and systemic lupus erythematosus.
The risk of developing complications is high if the disorder is left untreated. For instance, due to lack of essential proteins, it’s likely that blood clots will form and go into the lungs. The kidneys and heart are also at risk of failing in severe cases.
One of the most common symptoms that a patient with nephrotic syndrome will display is edema (swelling). This mostly occurs around the eyes or facial area, the abdomen, and in the upper and lower extremities.
The patient will also notice foamy urine, unexplained weight loss or weight gain due to fluid retention, and a poor appetite.
Other symptoms include stomach pain, muscle wasting, orthostatic hypotension, and a general feeling of being unwell.
Who to See & Types of Treatment Available
Patients who display the above symptoms, should consult their family doctor. The symptoms are common in many different types of disorders and diseases, so the doctor will often require a detailed medical history. A physical examination and several tests will also be conducted to determine the cause of the symptoms.
If the doctor suspects the presence of kidney problems, the patient will be referred to a nephrologist (specialist in kidney functions) for further evaluation and treatment.
If the nephrologist suspects nephrotic syndrome, a urine and blood test will be conducted. Urine tests will include a urinalysis and a creatinine clearance test to determine the amount of proteins in the urine. The patient will be required to collect urine samples at different times within a 24-hour period to come up with accurate measurements.
Blood tests will include an albumin test, blood chemistry, and blood urea nitrogen (BUN). These tests will determine if the amount of proteins in the blood are below the recommended levels. The cholesterol and triglycerides levels will also be checked; high levels indicate reduced levels of albumin.
Since the disorder can be caused by a wide variety of medical conditions, pinpointing the exact cause can be a meticulous task. It’s likely that the specialist will also request a kidney biopsy to determine what’s causing nephrotic syndrome.
It’s imperative that the doctor is able to identify the exact cause of the disorder to provide the correct treatment plan. Treatment for nephrotic syndrome will depend on the underlying condition. But medications will also be provided to control the symptoms.
The common medications used in treating nephrotic syndrome are the following:
Blood pressure medications – Elevated blood pressure will likely create more problems. Taking blood pressure medications will reduce the risk of other complications.
Cholesterol medications – Reduced albumin levels result in increased cholesterol levels. High cholesterol increases the risk of heart-related problems, which is why ideal cholesterol levels need to be maintained through medications.
Water pills – Diuretics force excess water out of the body by inducing the kidneys to increase fluid output. This leads to reduced swelling in the abdomen, arms, face, and legs.
Anticoagulants – Patients with nephrotic syndrome are at risk of developing blood clots that can travel to the lungs and cause further damage. Anticoagulants (blood thinners) prevent the formation of blood clots.
Immune system suppressants – Kidney disorders, such as MCD, are a result of an overly active immune system. Immune suppressant medications reduce inflammation caused by the immune system.
In addition to the above medications, the doctor will also provide treatment for any organs that have been damaged because of nephrotic syndrome. If the damage to the organ is severe, surgery may be required to repair the damage or replace the organ, such as in a kidney transplant.
Although medications help in reducing the symptoms, patients are often required to make some lifestyle changes to help cope with the complications of the disorder. It is possible that a dietician will be brought into the case to inform the patient about the correct diet while he or she is on medications. The diet could include reducing the amount of fatty food and increasing intake of high protein foods. The intake of sodium (salt) must also be reduced.
It’s important to note that in some cases, nephrotic syndrome does not respond to medications. If this happens, the doctor will advise the patient to take vitamin D supplements because treatment could take a while. If the kidney begins to fail during treatment, the patient will undergo dialysis or a kidney transplant, in case of total organ failure.
Appel GB. Glomerular disorders and nephrotic syndromes. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 122.
Nachman PH, Jennette JC, Falk RJ. Primary glomerular disease. In: Brenner BM, ed. Brenner and Rector's The Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 30.