Kidney values

Introduction

Kidney values are among the very important and most frequently examined values in the blood count. The kidney values provide information about the condition of the kidneys and whether they are working sufficiently. An increase in kidney values that exceeds the norm requires extensive and timely examinations of the kidneys.

The most important kidney values are the creatinine value and, in connection with this, to a certain extent the potassium value. Creatinine is a waste product of metabolism, which is filtered through the kidneys and passes into the urine, with which it is then excreted. The increase in potassium, which indicates disease and insufficient functioning of the kidneys, is also related to kidney activity.

The kidneys act as a filter system through which vital substances are retained in the body and waste products are excreted. If the kidneys become diseased and can no longer perform the filtering work in the usual and necessary way, the amount of creatinine washed out of the blood and into the urine is reduced. Furthermore, the so-called glomerular filtration rate, also called GFR, is determined in almost every blood count. The GFR indicates how much filtrate per minute the kidneys pass through. A reduction in GFR also indicates a disease of the kidney, in which case further examination is necessary.

What are the important kidney values?

Kidney values are the so-called renal retention values. These are substances that are almost exclusively excreted via the kidneys and urine. If the kidneys are damaged or the kidney function is restricted, these renal retention values in the blood increase because excretion via the kidneys is disturbed.

The most frequently determined kidney value is creatinine, a breakdown product, the creatine that acts as an energy store in the muscles. The determination of creatinine concentrations allows indirect conclusions about the glomerular filtration rate (GFR). The GFR is the most important marker for monitoring kidney function and indicates how well the kidneys filter the blood.

Other kidney values that can be measured in the blood are urea, uric acid and cystatin C. These values serve as a supplement to the creatinine value, as this is very susceptible to interference, and can also give an indication of other diseases. In addition, electrolyte concentrations (especially sodium, potassium and chloride) are often determined in connection with a laboratory chemical examination of kidney function. Creatinine is an important part of the laboratory parameters in everyday clinical practice.