Kidney function tests are physical examinations and procedures, used by a medical doctor, to test kidney function and evaluate how well the kidneys are working.
The kidneys are the primary organs of the body's natural filtration system.
Their functions include: removing waste products from the bloodstream, regulating the body's water balance, and maintaining the pH (acidity/ alkalinity) of the body's fluids.
Many conditions can affect the ability of the kidneys to carry out their vital functions. Some lead to a rapid (acute) decline in kidney function, while others lead to a gradual (chronic) decline in kidney function. Both result in the accumulation of toxic wastes and excess fluids in the blood.
It is possible to determine the extent of kidney dysfunction by performing a variety of kidney function tests. These tests primarily involve analyses of the urine and blood. The chemical composition of these two substances (blood and urine) can reveal a great deal of information about the efficiency of the kidneys and how well they are doing their jobs.
The main job of the kidneys is to remove waste products and toxic chemicals from the blood and eliminate them from the body, via the urine. In order to test kidney function, doctors consider the rate at which the kidneys remove waste and toxic products from the blood and the quantity and composition of the chemicals excreted by the kidneys.
The following are some typical kidney tests, which are used to assess kidney function.
In addition to the many kidney tests that require urine evaluation, the blood can also be evaluated to determine kidney function. For example, blood tests which measure the levels of sodium, potassium, chloride, bicarbonate, calcium, magnesium, phosphorus, protein, uric acid, and glucose, can help to determine how well the kidneys are working.
After completing a series of kidney function tests, if it is determined that kidney function is impaired, it may be necessary to perform a full assessment of the kidneys in order to determine the underlying cause of kidney failure and whether the kidney failure is chronic or acute. Kidney tests such as magnetic resonance imaging (MRI), computed tomography (CT) scan, ultrasound, X rays, renal biopsy, and arteriogram (the recording of an arterial pulse) of the kidneys can help to determine the cause of kidney failure and the level of remaining kidney function.
Kidney function tests are most effective in determining whether someone has kidney failure and also measuring the severity of the condition, which is determined by the level of kidney function.