- Reference values for the urea test
- What the exam result means
- 1. High urea
- 2. Low urea
- When the exam is indicated
The urea test is one of the blood tests ordered by the doctor that aims to check the amount of urea in the blood to find out if the kidneys and liver are functioning properly.
Urea is a substance produced by the liver as a result of the metabolism of proteins from food. After metabolism, urea circulating in the blood is filtered through the kidneys and eliminated in the urine. However, when there are problems with the liver or kidneys, or when you have a diet rich in protein, the amount of urea circulating in the blood increases, characterizing uremia, which is toxic to the body. Learn to identify the symptoms of uremia.
Most of the time, the urea test is requested together with other tests, mainly creatinine, because it is possible to better evaluate the functioning of the kidneys for the filtration of blood.
Reference values for the urea test
The values of the urea test may vary according to the laboratory and technique used for the dosage, however the reference values normally considered are:
- For children up to 1 year: between 9 and 40 mg / dL; For children over 1 year: between 11 and 38 mg / dL; For adults: between 13 and 43 mg / dL.
To perform the urea test, it is not necessary to be fasting or perform any other preparation, and the test is done by collecting a small amount of blood, which is sent to the laboratory for analysis.
What the exam result means
The result of the urea test must be evaluated by the doctor who ordered the test along with other tests that have been requested, the result being considered normal when within the reference values.
1. High urea
The increase in the concentration of urea in the blood may indicate that there is a large amount of urea being metabolized by the liver or that the kidneys are not working properly, with changes in the blood filtration process. Some situations that can lead to increased blood urea are:
- Renal failure; Decreased blood flow to the kidneys, which may be due to Congestive Heart Failure and Infarction, for example; Severe burns; Dehydration; Protein-rich diet.
For this reason, it is important to identify the disease and start appropriate treatment, and the use of drugs to control the pressure and the amount of urine or dialysis may be indicated, which is usually indicated in the most severe cases when other parameters are also changed.
When increased urea is a consequence of dehydration, for example, it is recommended to increase the intake of plenty of fluids during the day, as this makes it possible to normalize blood urea levels. In the case of increased urea due to food, it is recommended to adjust the diet, preferably with the help of a nutritionist, as it is possible to know the most suitable foods without risking nutritional deficiencies.
2. Low urea
The decrease in the amount of urea in the blood is not normally a cause for concern, which may be due to lack of protein in the diet, malnutrition, pregnancy, low absorption of the intestine or the inability of the liver to metabolize the protein, as in liver failure.
When the exam is indicated
The urea exam is requested by the doctor in order to assess kidney function and monitor the response to treatment and progression of kidney diseases. The test can also be ordered when the person has symptoms of uremia or kidney problems, such as excessive tiredness, urinary problems, increased blood pressure, urine with foam or blood or swelling of the legs, for example.
Thus, in addition to requesting the dosage of urea, the dosage of creatinine, sodium, potassium and calcium may also be recommended. In addition, a 24-hour urine test may be indicated, the collection of which must begin after blood is collected for the test, to check the amount of urea released into the urine. Understand how the 24-hour urine test works.
