Kidney Failure

The kidneys are complex organs that perform many functions, including maintenance of fluid and acid–base balance, removal of waste products, stimulation of red blood cell production, and regulation of calcium stores. Failure of the kidney can affect one or all of these functions, and may occur suddenly or gradually. Physicians commonly use creatinine, a blood test, to estimate the kidney's function. The glomerular filtration rate (GFR) reflects how much fluid one glomeruli (the smallest functioning unit in the kidney) can filter per minute.

Sudden or acute kidney failure can be caused by poor blood flow to the kidney as with dehydration or heart failure, very high blood pressure, toxins, inflammation, or kidney stones, to name a few possibilities. Patients can present with confusion, reduced appetite, vomiting, leg swelling, or reduced urine output. Acute kidney failure is managed by treating the underlying cause and allowing the kidneys to heal themselves. If needed, physicians can remove excess fluid or waste products directly from the blood by using hemodialysis for a short period.

Chronic kidney failure, on the other hand, is a gradual and largely silent disease caused most often by uncontrolled diabetes and hypertension. One in nine adults in the United States has chronic kidney disease (CKD). Racial and ethnic minorities and people with obesity and associated conditions like hypertension, diabetes, and hypercholesterolemia are at higher risk for kidney failure.

Simple tests like creatinine and urine protein can identify people with early stages of CKD. Early intervention with medications to treat hypertension, such as angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), and lower blood sugar can slow or even halt disease progression.

People with advanced CKD commonly develop poor appetite, loss of sleep, lack of energy, poor concentration, muscle cramps at night, and swollen feet. CKD itself can cause high blood pressure and increase cholesterol deposition in arteries, thereby predisposing to heart attack and stroke.

People with CKD should avoid taking over-the-counter pain medications, and take new medications only after proper consultation with a physician. Because damaged kidneys cannot process high levels of potassium, sodium, or protein, a modified diet is recommended. In addition to monitoring the GFR, physicians also monitor calcium, vitamin D, and red blood cell levels. Treatment with vitamin D to prevent osteoporosis or erythropoietin to treat anemia may be necessary. In end-stage CKD, patients may require hemodialysis, peritoneal dialysis, or kidney transplant to survive.

Acute kidney failure is managed by treating the underlying cause and allowing the kidneys to heal themselves.