Kidney Disease

There are many types of kidney disease, most of which are potentially serious.  Whether you get kidney disease is mostly due to bad luck, but whether it progresses to end-stage kidney failure does depend largely on what is done about it. Some kidney diseases are genetic, such as Polycystic Kidney Disease (PKD).  The kidneys become filled with cysts, which cause the kidneys to become less effective, and eventually leads to kidney failure.  A variant of PKD is not usually detected until adulthood.  This is known as "adult PKD", as the symptoms usually do not occur until patients are well into adulthood.  However, with advances in diagnostic imaging technology, doctors are gradually becoming able to detect these conditions before symptoms appear.

The kidneys, two fist-sized organs weighing about 150gm each, are located on either side of the spine just above the waist and perform a life-sustaining role.  They cleanse the blood and help regulate blood pressure.  Each adult kidney is composed of about 1 million nephrons that drain about 14 calyces.

The kidneys make renin and erythropoietin, and convert vitamin D into its useful form.  More importantly, by forming urine they perform three important functions:

1. The kidneys excrete the waste products of metabolism.  A patient with any sort of impaired kidney function will have increased creatinine and urea nitrogen in the blood, or azotemia.  If the kidney is adequately perfused, is itself normal, and its outflow not obstructed, blood urea nitrogen levels will remain within normal limits.
2. The kidneys regulate the body's content of water, sodium, and potassium.  Hypertension, edema, and/or hyperkalemia may develop in renal disease.  Renal edema is first visible around the patient's eyes.
3. The kidneys maintain the appropriate acid-base balance of plasma.  Metabolic acidosis is characteristic of severe renal failure.

Causes and Development; Contributing Risk Factors

High blood pressure, anemia, and bone demineralization are common in serious kidney disease.  Renal insufficiency due to underperfusion (dehydration, shock or a failing heart) or due to obstruction is extremely common.  High blood pressure commonly result from kidney problems, and always damages the kidneys to some extent.

Once the kidney is damaged to a certain degree, it continues to deteriorate (i.e., undergo more scarring, notably glomerular sclerosis) even if the underlying disease is cured.  [Lancet 338: pp.419 & 423, 1991]

Kidney Failure: Loss of Renal Function
Acute renal failure usually manifests itself as oliguria plus azotemia.  Hyperkalemia is the main threat to life during the oliguric phase.

Chronic renal failure is the end result of irreversible kidney damage from any cause.  Sometimes the cause of the "end-stage contracted kidney" cannot be determined even at autopsy.  Once a sufficient number of nephrons are destroyed, it causes the remainder of them to die off inexorably.

Anuria, the complete cessation of urine production, is rare in acute renal failure – the major exception being diffuse cortical necrosis.  It may occur late in chronic renal failure.  Much more often though, anuria is due to obstruction of ureters or urethra.

African-Americans are more at risk for end-stage kidney disease, for reasons that include a greater severity and frequency of hypertensive kidney disease in this population.  Whether their problems are neglected by doctors, or treated less skillfully is an open question.  [Ann.  Int.  Med.  155: p.1201, 1995]

Signs and Symptoms

When the kidneys become diseased or damaged, they can suddenly or gradually lose their ability to perform their vital functions.  Waste products and excess fluid then build up inside the body, causing a variety of symptoms, particularly swelling of the hands and feet, shortness of breath, and a frequent urge to urinate.

Symptoms include: increased urination at night; the passing of very small amounts of urine (oliguria); swelling, particularly of the hands and feet; puffiness around the eyes; azotemia (Increased levels of urea in blood); unpleasant taste in the mouth and urine-like odor to the breath; persistent fatigue or shortness of breath; loss of appetite; increasingly higher blood pressure; pale skin; excessively dry, persistently itchy skin.  In children: increased fatigue and sleepiness; decrease in appetite; and eventually, poor growth.

Treatment and Prevention

Since the kidneys need to process a huge amount of daily waste, adequate water intake is essential for them to continue functioning properly.  Using kidney herbs occasionally or going on a kidney cleanse once or twice a year is a good practice to reduce the likelihood of progressive kidney damage or stone formation.

There are many kidney cleansing products available at health food stores.  Any of them should generally be safe to use in moderation.

Prognosis

If left untreated, diseased kidneys may eventually stop functioning.  Loss of kidney function is a very serious and potentially fatal condition.

Spontaneous recovery of renal function is rare but does occur (around 1%, more in patients with lupus) [Am.  J.  Kid.  DIs.  15: p.61, 1990].