Encyclopedia of Health and Medicine

nephrotoxins 211
• frothy URINE during URINATION (indicates albuminuria)
• edema (fluid accumulation in the tissues), most
noticeable upon awakening and often affecting
the face and the feet
• fatigue
• loss of APPETITE in combination with increased
weight (weight gain results from edema)
• HEADACHE
Some forms of nephropathy also cause painless
HEMATURIA (bloody urine). The diagnostic path
includes further urine tests as well as BLOOD tests
to assess kidney function. The nephrologist may
perform a kidney biopsy to examine the nephrons
under the microscope, which reveals the microscopic
damage of nephropathy. The nephrologist
may also conduct diagnostic imaging procedures
such as COMPUTED TOMOGRAPHY (CT) SCAN and INTRA-
VENOUS PYELOGRAM (IVP) to examine kidney structure
and function.
Treatment Options and Outlook
Treatment targets the underlying condition with
the aim of slowing progression of the nephropathy
and preserving remaining kidney function. It is
critically important for people who have diabetes
or hypertension (or both) to maintain effective
control of these conditions through medication
therapy and lifestyle measures. Some people are
able to successfully manage the underlying condition
and the nephropathy to avoid ESRD, though
often nephropathy progresses to require RENAL
DIALYSIS. Whether kidney transplantation is a
viable treatment option for ESRD resulting from
nephropathy depends on multiple factors, including
co-existing health conditions, age, and overall
health status.
Risk Factors and Preventive Measures
Diabetes and hypertension combined cause more
two thirds of nephropathy in the United States.
The risk for nephropathy is particularly high for
people who have both these conditions. Preventing
these conditions and appropriately and diligently
treating them when they develop mitigates
the risk for nephropathy. People who take longterm
NSAIDs to treat chronic conditions such as
OSTEOARTHRITIS should have regular blood and
urine tests to screen for early indications of
nephropathy, and work with their doctors to find
the lowest effective DOSE and least nephrotoxic
medication to manage the condition and its symptoms.
See also HEAVY-METAL POISONING; HEPATORENAL
FAILURE; NEPHRITIS; NEPHRON; NEPHROTIC SYNDROME;
RETINOPATHY.
nephrotic syndrome A constellation of symptoms
that result as a consequence of conditions
that damage the glomeruli within the renal
nephrons. The damage allows excessive protein to
move through the walls of the glomeruli into the
filtrate. The tubules are unable to reabsorb the
large protein molecules, so the body ends up
excreting the protein in the URINE (ALBUMINURIA).
The excessive excretion of protein results in
HYPOALBUMINEMIA, or low levels of ALBUMIN in the
BLOOD circulation. The hypoalbuminemia allows
fluid to leave the blood circulation and enter the
interstitial tissues, where it accumulates to cause
edema (swelling). Because the blood volume is
now low, the KIDNEYS compensate by reabsorbing
higher levels of water and sodium.
Most people who have nephrotic syndrome
have diagnosed kidney disease so the underlying
cause is clear. When indications of nephrotic syndrome
occur in someone who does not have kidney
disease, the diagnostic path begins with blood
and urine tests to assess kidney function. Further
diagnostic procedures then strive to identify the
underlying renal condition. Treatment targets the
underlying renal condition as well as symptoms
such as HYPERTENSION (high BLOOD PRESSURE) and
RENAL FAILURE. Treatment may include RENAL DIALY-
SIS when renal function is significantly impaired.
The outlook depends on the underlying renal condition
and its response to treatment. Symptoms of
nephrotic syndrome generally resolve when the
underlying condition improves.
See also GLOMERULONEPHRITIS; GLOMERULOSCLERO-
SIS; MINIMAL CHANGE DISEASE; NEPHRITIS; NEPHRON;
UREMIA.
nephrotoxins Substances such as medications or
environmental chemicals that damage the
glomeruli and the tubules within the nephrons of