Every human body contains one pair of kidneys. They are situated towards the back of the body under the ribs, just at the level of the waist, with one on each side of the body. Each kidney is composed of about one million units called nephrons, and each nephron consists of two parts: a filter, called the glomerulus and a tubule leading out from the nephrons (Cameron 1999). According to Marshall and Bangert (2008), the kidneys have three major functions: firstly, the kidneys excrete waste from plasma in the blood. Secondly, they maintain extracellular fluid volume and composition. Lastly, the kidneys play a role in hormone synthesis.
There are many diseases that might infect the kidneys and affect their functioning. One of these diseases is renal failure (kidney failure), a dangerous disorder. Stein (2002) defines renal failure as a condition in which the kidneys are less able than normal to do their usual function. There are two classes of kidney failure: acute renal failure (ARF) and chronic renal failure (CRF). This essay will focus on CRF and explain its two major causes.
Chronic Renal Failure
Chronic renal failure is progressive destruction of kidney tissue by disease; if not treated by dialysis (removal of waste substances from the blood of a patient who suffers from kidney failure) or transplantation (the transfer of an organ such as a kidney from one person to another), CRF will result in death of the patient. Gaw et al. (2008) identified the differences between ARF and CRF: kidneys in ARF fail over a period of days or hours, whereas CRF develops over years or months. In addition, ARF can be reversed, which means normal kidney function can be recovered, but CRF is irreversible. According to a report issued by the Centers for Disease Control and Prevention in 2004, almost 19 million adults have chronic kidney disease in the United States, and an estimated 80,000 patients have CRF diagnosed annually (www.cdc.gov). However, when the kidneys stop working completely, the situation known as end-stage renal failure (ESRF) occurs in CRF. Some diseases may cause CRF when patients are infected for a long time.
One of the diseases that can cause CRF is diabetes mellitus, a major cause of renal failure. This disease can be defined as an increase in fasting blood glucose as a result of a deficiency in insulin, which is a hormone. The normal range for glucose (fasting) in the blood is 2.8 - 6.0 mmol/L. Diabetes Mellitus is classified into two groups: type 1 (insulin-dependent) and type 2 (non insulin-dependent). The difference between them is that, in type 1, the body does not produce enough insulin, but in type 2 the body does not make effective use of this hormone. Stein (2008, p. 6) points out that kidney failure most often occurs when patients have suffered from diabetes mellitus for more than 10 years.
According to a report by the U.S. Renal Data System (USRDS) in 2007, the...