Renal Failure, Chronic

Risk: In the US, those at highest risk for chronic renal disease are individuals with diabetes and hypertension. Disease conditions or toxins that directly affect kidney function increase risk.

Incidence and Prevalence: An estimated 4.5% of all adults over age 20 (7.4 million) have some evidence of chronic kidney disease ("Annual Data Report"). Approximately 392,000 people with ESRD are treated annually; of those, about 93,000 cases are new, and 76,000 people die each year ("Annual Data Report"). Over 200,000 individuals with ESRD undergo dialysis each year. About 15,000 kidney transplants are performed a year in the US ("Annual Data Report"), and 72,000 individuals are estimated to be living with functioning kidney transplants.

History: The progression of kidney disease may be so gradual that symptoms are not obvious until kidney function is down to one-tenth of normal. Individuals may initially report nonspecific symptoms such as nausea and vomiting, fatigue, itching (pruritus), headaches, forgetfulness, unintentional weight loss, and malaise. They may also report symptoms that include loss of appetite (anorexia), decreased exercise tolerance, difficulty breathing, chest pain, problems with taste, mood changes, and sleep disturbances. Some individuals may report a family history of kidney disease. Later symptoms include increased or decreased urinary output, increased nocturnal urination (nocturia), excessive thirst, easy bruising or bleeding, and blood in stool or vomitus.

Physical exam: The exam may reveal dry, brittle, and pale yellow- or brown-toned skin (sallow complexion), an ammonia odor on the breath, hair loss, nail changes, a rapid heartbeat, heart murmur, loss of sensation in the hands or feet, altered mental status (drowsy and lethargic or agitated and confused), brownish discoloration of the tongue, muscle twitching or cramping, and hand flapping when the arms are extended (asterixis). It may also reveal accumulation of fluid in the tissues of extremities (edema), increased blood pressure (hypertension), fluid in the abdominal cavity (ascites), congestive heart failure, and pericardial effusion. Physical examination may also reveal enlarged kidneys when the abdomen is touched with the fingertips (palpated); abnormal heart or lung sounds may be heard with a stethoscope (auscultation). An eye examination may reveal abnormalities associated with hypertension, diabetes, or other metabolic conditions. A neurologic exam may show changes in several of the peripheral nerves (polyneuropathy).

Tests: Diagnostic tests typically include laboratory examination of blood and urine, diagnostic imaging, and a kidney biopsy if the cause of the chronic renal failure remains unclear. A complete blood count (CBC) may reveal anemia. Electrolyte levels may be abnormal, showing an imbalance of potassium, sodium, and chlorides and increased levels of calcium, phosphate, and magnesium. Other blood chemistries and arterial blood gas testing may reveal reduced bicarbonate and metabolic acidosis. Blood urea nitrogen (BUN) and creatinine levels will typically be elevated. The parathyroid hormone (parathormone) level may be elevated. Routine urinalysis may reveal an abnormal pH indicative of acid concentration; a high specific gravity indicating an abnormal concentration of solids and water; and the presence of protein (albumin), glucose, ketones, or blood in the urine. All urine produced for a 24-hour period may be collected. Additional diagnostic tests may include ultrasound, which may reveal structural abnormalities in the urinary tract or abnormalities in the size of the kidneys. A renal biopsy may reveal cellular changes in kidney tissues that are associated with chronic renal failure. Other imaging tests may include a renal or abdominal x-ray, CT scan, or MRI. A contrast scan (using injection of radiopaque dye or contrast material) may also be performed to evaluate kidney function.