Nephrotic Syndrome

Nephrotic syndrome can be

A variety of primary kidney disorders can damage the glomeruli and cause nephrotic syndrome. Minimal change disease is the most common cause of nephrotic syndrome in children.

The secondary causes may involve other parts of the body. The most common disorders causing nephrotic syndrome are diabetes mellitus Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more , systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more (lupus), and certain viral infections. Nephrotic syndrome can also result from kidney inflammation (glomerulonephritis Glomerulonephritis Glomerulonephritis is a disorder of glomeruli (clusters of microscopic blood vessels in the kidneys with small pores through which blood is filtered). It is characterized by body tissue swelling... read more ). A number of medications that are toxic to the kidneys can also cause nephrotic syndrome, especially nonsteroidal anti-inflammatory drugs Nonsteroidal Anti-Inflammatory Drugs Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most pain... read more (NSAIDs). The syndrome may be caused by certain allergies, including allergies to insect bites and to poison ivy or poison oak. Some types of nephrotic syndrome are hereditary.

Early symptoms include

The abdomen may be swollen because of a large accumulation of fluid in the abdominal cavity (ascites Ascites Ascites is the accumulation of protein-containing (ascitic) fluid within the abdomen. Many disorders can cause ascites, but the most common is high blood pressure in the veins that bring blood... read more ). Shortness of breath may develop because fluid accumulates in the space surrounding the lungs (pleural effusion Pleural Effusion Pleural effusion is the abnormal accumulation of fluid in the pleural space (the area between the two layers of the thin membrane that covers the lungs). Fluid can accumulate in the pleural... read more ). Other symptoms may include swelling of the labia or scrotum. Most often, the fluid that causes tissue swelling is affected by gravity and therefore moves around. During the night, fluid accumulates in the upper parts of the body, such as the eyelids. During the day, when the person is sitting or standing, fluid accumulates in the lower parts of the body, such as the ankles. Swelling may hide the muscle wasting that is progressing at the same time.

In children, blood pressure is generally low, and blood pressure may fall when the child stands up (orthostatic or postural hypotension) Dizziness or Light-Headedness When Standing Up In some people, particularly older people, blood pressure drops excessively when they sit or stand up (a condition called orthostatic or postural hypotension). Symptoms of faintness, light-headedness... read more . Shock Shock Shock is a life-threatening condition in which blood flow to the organs is low, decreasing delivery of oxygen and thus causing organ damage and sometimes death. Blood pressure is usually low... read more occasionally develops. Adults may have low, normal, or high blood pressure.

Urine production may decrease, and kidney failure Overview of Kidney Failure Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney failure has many possible causes. Some lead to a rapid decline in kidney function... read more (loss of most kidney function) may develop if the leakage of fluid from blood vessels into tissues depletes the liquid component of blood and the blood supply to the kidneys is diminished. Occasionally, kidney failure with low urine output occurs suddenly.

Nutritional deficiencies may result because nutrients are excreted in the urine. In children, growth may be stunted. Calcium may be lost from bones, and people may have a vitamin D deficiency, Vitamin D Deficiency Vitamin D deficiency is most commonly caused by a lack of exposure to sunlight. Some disorders can also cause the deficiency. The most common cause is lack of exposure to sunlight, usually when... read more leading to osteoporosis. Osteoporosis Osteoporosis is a condition in which a decrease in the density of bones weakens the bones, making breaks (fractures) likely. Aging, estrogen deficiency, low vitamin D or calcium intake, and... read more The hair and nails may become brittle, and some hair may fall out. Horizontal white lines may develop in fingernail beds for unknown reasons.

The membrane that lines the abdominal cavity and abdominal organs (peritoneum) may become inflamed and infected. Opportunistic infections—infections caused by normally harmless bacteria—are common. The higher likelihood of infection is thought to occur because the antibodies that normally combat infections are excreted in the urine or not produced in normal amounts. The tendency for blood clotting Excessive Clotting Excessive clotting (thrombophilia) occurs when the blood clots too easily or excessively. Inherited and acquired disorders can increase blood clotting. Clots in larger blood vessels cause legs... read more (thrombosis) increases, particularly inside the main veins draining blood from the kidneys. Less commonly, the blood may not clot when clotting is needed, generally leading to excessive bleeding. High blood pressure accompanied by complications affecting the heart and brain is most likely to occur in people who have diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more or systemic lupus erythematosus. Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more

A doctor bases the diagnosis of nephrotic syndrome on symptoms, physical examination findings, and laboratory findings. Sometimes nephrotic syndrome is at first mistaken for heart failure in older adults because swelling occurs in both disorders and heart failure is common among older people.

A laboratory test of urine collected over a 24-hour period is useful for measuring the degree of protein loss, but collection of urine over such a long period is difficult for many people to accomplish. Alternatively, to estimate protein loss, a single urine specimen can be tested to measure the ratio of the level of protein to that of creatinine (a waste product).

Blood tests and other urine tests detect additional characteristics of the syndrome. The level of albumin in the blood is low because this vital protein is excreted in the urine and its production is impaired. The urine often contains clumps of cells that may be combined with protein and fat (casts). The urine contains low levels of sodium and high levels of potassium.

Concentrations of lipid in the blood are high, sometimes exceeding 10 times that of a normal concentration. Levels of lipid in the urine are also high. Anemia Overview of Anemia Anemia is a condition in which the number of red blood cells is low. Red blood cells contain hemoglobin, a protein that enables them to carry oxygen from the lungs and deliver it to all parts... read more may be present. Levels of blood clotting proteins may be increased or decreased.

The prognosis varies depending on the

Symptoms may disappear completely if the nephrotic syndrome is caused by a treatable disorder, such as an infection, cancer, or medications, provided the condition is treated early and effectively. This situation occurs in about half the cases in children but less often in adults. If the underlying disorder responds to corticosteroids, sometimes progression of the disease is halted, and less often the condition partially or, rarely, completely reverses. When the syndrome is caused by human immunodeficiency virus (HIV) infection Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and is treated with antiretroviral medications. If untreated, it can cause... read more , it usually progresses relentlessly, often resulting in complete kidney failure in 3 or 4 months. Children born with nephrotic syndrome rarely live beyond their first birthday, although a few have survived by means of dialysis Dialysis Dialysis is an artificial process for removing waste products and excess fluids from the body, a process that is needed when the kidneys are not functioning properly. There are a number of reasons... read more treatments or a kidney transplant. Kidney Transplantation Kidney transplantation is the removal of a healthy kidney from a living or recently deceased person and then its transfer into a person with end-stage kidney failure. (See also Overview of Transplantation... read more

When the cause is systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more or diabetes mellitus, Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more medications often stabilize or decrease the amount of protein in the urine. However, some people do not respond to medications and develop chronic kidney disease Chronic Kidney Disease Chronic kidney disease is a slowly progressive (months to years) decline in the kidneys’ ability to filter metabolic waste products from the blood. Major causes are diabetes and high blood pressure... read more , which then progresses to kidney failure within a few years.

Use of an angiotensin-converting enzyme (ACE) inhibitor, such as enalapril, benazepril, or lisinopril, or an angiotensin II receptor blocker (ARB), such as candesartan, losartan, or valsartan, is the mainstay of both prevention and treatment. When a person with a disease such as systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more or diabetes mellitus Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more has mild or moderate proteinuria, an ACE inhibitor or ARB is used as soon as possible because the medication may prevent proteinuria from increasing and kidney function from worsening.

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