Ammonia is produced following the degradation of amino acids (basic substances of proteins that contribute to the construction of organic tissues).
Urea is transformed in the liver and released into the bloodstream, only to be eliminated in the urine, after being filtered by the kidneys. For this reason, its evaluation in the blood is useful for monitoring kidney function.
Normal azotemia values are between 15 and 50 mg / dl (milligrams per deciliter of blood), with a variability that depends on "age and sex. Values other than the reference ones indicate an" imperfect blood purification by the kidneys.
Typical conditions of azotemia are found mainly in the presence of a decreased function of the kidneys. This can be caused by dehydration or heart failure, acute or chronic kidney disease, a high-protein diet and drug therapy with toxic effects on the liver.
A decrease in azotemia values can be caused by diets that are too low in protein or carbohydrates, liver failure, poisoning and nephrosis.
In the presence of impaired renal function, the body is unable to eliminate nitrogenous waste from the blood resulting from protein catabolism. The resulting accumulation in the bloodstream is responsible for the increased azotemia (azotemia).
, the results of this test are considered an index of renal function.The examination is indicated in the presence of:
- Non-specific malaise;
- Signs or symptoms that lead to suspicion of some kidney disorder;
- Chronic diseases such as diabetes and heart failure (check at regular intervals).
In addition, azotemia can be prescribed by the doctor in order to:
- Assess whether the kidneys are functioning before starting certain drug therapies;
- Monitor the effectiveness of dialysis or other treatments in patients with chronic and acute kidney disease.
This data refers to the plasma concentration of urea.
Some laboratories use different analytical methods, referring to the concentration of urea nitrogen (BUN) which constitutes about half of the urea molecule. In this case the physiological values of azotemia are included in the range from 10.3 to 21.4 mg / dl.
, they will probably have discovered that their blood urea nitrogen levels are close to, or even higher than, the maximum value considered normal. The phenomenon is all the more evident the more the water intake is reduced.
On the contrary, the high synthesis of protein metabolites can be compensated by an abundant intake of liquids which, causing polyuria, on the one hand increases the urinary elimination of urea and on the other hand lowers the plasma concentration of the metabolite.
