Chronic kidney disease (CKD) is any degree of impairment of kidney function. It is usually silent, detected by a blood or urine test, and usually causes no symptoms. CKD is most commonly associated with diabetes, high blood pressure, or other disorders. It progresses slowly over a period of years.
The kidneys filter wastes and excess fluids from the blood, which are then excreted in the urine. When chronic kidney disease reaches an advanced stage, dangerous levels of fluid, electrolytes and wastes can build up in the body. At that time, dialysis (temporary or permanent) is used to perform the function of the failing kidneys. While 26 million Americans have some degree of CKD, only 500,000 develop end-stage renal disease (kidney failure), requiring dialysis or kidney transplantation.
Chronic kidney disease is identified by a blood test for “creatinine,” which is a breakdown product of muscle metabolism. Higher levels of creatinine indicate a lower glomerular filtration rate and, as a result, a decreased capability of the kidneys to excrete waste products.
The National Kidney Foundation has created guidelines to help identify each level of kidney disease, as it can be progressive in nature. Chronic kidney disease is divided into five stages. Stage 1 is normal kidney function, while Stage 5 represents end-stage kidney disease, requiring dialysis to maintain health. Stage 3 is considered moderately impaired kidney function.
Acute kidney injury (AKI) was previously called acute renal failure. It is usually precipitated by another medical problem, such as an acute illness or surgery, or by exposure to a toxic agent. It is often temporary but can be very serious and dangerous. The temporary use of dialysis may be required until the kidneys recover. People who have experienced AKI may have an increased risk of chronic kidney disease in the future. Management includes treatment of the underlying cause and supportive care, such as dialysis.
Chronic kidney disease medical expert witness specialties include nephrology and dialysis nursing.