Kidney disease is a very common cause of serious illness, affecting more than 25 million Americans. Each year approximately 110,000 new patients start dialysis treatments in the US, and kidney disease is responsible for nearly 100,000 American deaths annually.
How do the kidneys work under normal circumstances?
Our kidneys are a pair of bean-shaped, fist-sized organs that work diligently and silently behind the scenes constantly, filtering our blood free of toxins and waste products so that we can maintain a healthy existence. When they are working well, they are often taken for granted. The renal arteries bring blood to the kidneys, the kidneys do their magic, and the cleansed and purified blood is returned into the renal veins, with the liquid waste—urine—excreted into the ureters that drain into the urinary bladder.
If the kidneys stop working properly, excessive fluid and toxic waste builds up rapidly, resulting in death within a matter of days to weeks. Death by kidney failure is described as “euphoric” because of the very abnormal blood chemistries and electrolyte disturbances that occur…not that death is something to be “giddy” about, but kidney failure just happens to be an easier, more peaceful way to exit the planet than many others.
Because of their critical importance to our healthy existence, we should take great care of these prized possessions which nature gave us in duplicate. This “spare tire” is capable of sustaining life in the event of trauma, cancer requiring surgical removal, donating a kidney or other issues resulting in loss of one kidney.
The kidneys are multifunctional, not only filtering our blood to remove waste products, but also responsible for regulating fluid, electrolyte, acid-base balance and blood pressure. They are in charge of maintaining the proper fluid volume within our blood stream. They regulate the levels of our electrolytes including sodium, potassium, chloride, etc. They keep our blood pH (indicator of acidity) at a precise level to maintain optimal function. They are key players in the regulation of blood pressure. Furthermore—and unbeknownst to many—they are responsible for the production of several important hormones: calcitrol (calcium regulation), erythropoietin (red blood cell production), and renin (blood pressure regulation).
What is kidney disease?
Under normal circumstances, the kidneys filter the blood, removing waste products and excessive fluid, returning into circulation the body’s important chemicals and constituents. When the filtration system is not working properly, one’s system is not cleared of the bad (waste products), resulting in electrolyte disturbances and proteinuria, a condition in which what is good for the body (protein) ends up being filtered out into the urine.
When the kidneys fail (end stage renal disease), the options are peritoneal dialysis, hemodialysis, kidney transplantation, or death. Peritoneal dialysis uses the peritoneal membrane that lines the abdomen as a filter to clear wastes and extra fluid from the body. Hemodialysis involves being hooked up to a machine that mimics the function of the kidneys; it requires three sessions weekly that take about 3-4 hours per session.
What are the symptoms of kidney disease?
The unfortunate thing about kidney disease is that it typically causes few symptoms until it is advanced; however, simple tests are capable of detecting it. Symptoms of kidney disease are non-specific and may include the following:
- decreased energy
- poor appetite
- difficulty concentrating
- swollen ankles and feet
- nighttime muscle cramping
- puffiness around one’s eyes
- dry and itchy skin
- frequent urination, particularly at night
How is kidney disease diagnosed?
A definitive sign of kidney disease is the presence of protein in the urine, which is easily detectable on a urinalysis. Additionally, uncontrolled high blood pressure is highly suggestive of kidney disease, as is an elevated serum creatinine, detectable by a simple blood test. Early detection is critical as it can help prevent kidney disease from progressing to kidney failure. The bottom line is that three simple tests can detect kidney disease: blood pressure; serum creatinine; urine albumin (protein).
What are the risk factors for kidney disease?
Risk factors for kidney disease include:
- African-American race
- high blood pressure
- family history of kidney disease
The two leading causes of chronic kidney disease are hypertension and diabetes, responsible for about two thirds of cases.
How is kidney disease treated?
Urologists are the specialists who deal with surgical kidney issues whereas nephrologists are the specialists who deal with medical kidney tissues including hypertension and impaired kidney function. If kidney disease is diagnosed, one will typically be referred to a nephrologist for further evaluation and management. Nephrologists will typically measure the serum creatinine, and do blood and urine tests to assess the glomerular filtration rate, a quantitative test of kidney function. Often a renal ultrasound is performed and in some cases it is necessary to do a renal biopsy to find the root cause of the kidney dysfunction.
Treatment for progressive kidney disease includes interventions such as blood pressure control, often with the use of ACE inhibitors and angiotensin receptor blockers, and control of diabetes.
Nutritional interventions include dietary protein restriction that may slow the progression of chronic kidney disease. High-protein intake can worsen the proteinuria and result in the accumulation of various protein breakdown products as a result of decreasing kidney function, which can cause toxic effects.
How to prevent kidney disease
So how do we care for our kidneys? The prescription for healthy kidneys is to maintain a healthy lifestyle and, if you have been neglectful in this department, to do a lifestyle remake through the following: good eating habits; maintaining a healthy weight; engaging in exercise; obtaining adequate sleep; consuming alcohol in moderation; avoiding tobacco; and stress reduction.
Additionally, being proactive by seeing a physician on a regular basis for “scheduled maintenance” is very important in order to detect kidney disease—or any other disease—as early as possible.
Written by Dr. Andrew Siegel