The amino acids that are used or in excess are converted into ammonia and organic acids and sent to the liver. Since ammonia and organic acids are harmful to our body, they are sent to the liver to be broken down and rendered harmless. Ammonia undergoes certain processes in the liver and is converted to urea and excreted from the body. The stages of conversion of ammonia to urea are called the urea cycle.

Blood urea test

Some of the food taken with food consists of proteins. These proteins are converted into amino acids in our body and carried to the organs needed by the blood circulation. The amino acids that are used or in excess are converted into ammonia and organic acids and sent to the liver. Since ammonia and organic acids are harmful to our body, they are sent to the liver to be broken down and rendered harmless. Ammonia undergoes certain processes in the liver and is converted to urea and excreted from the body. The stages of conversion of ammonia to urea are called the urea cycle.

Since urea produced in the liver is water soluble, it can be excreted in the urine. It has been determined that urea is also found in small amounts in sweat, milk and tears. There is an increase in the blood level of urea, which cannot be excreted in the urine.



The upper limit of uric acid in the blood is 7-8 mg/dl in men and 6 mg/dl in women. In cases where there is an excess in its production and a decrease in its excretion, the blood level increases. As the height can be structural, the blood level increases as a result of some factors. An increase in the level of urea in the blood is called uremia.

Urea elevation is usually evaluated for monitoring renal failure and hemodialysis and monitoring the effectiveness of other treatments. Since the amount of urea excreted by the kidneys is produced above the kidney capacity can be associated with liver diseases, liver functions and possible diseases are also evaluated. On the other hand, a decrease in the level of urea excreted in the urine or in the blood below normal can also be an indicator of low urea production in the liver. In this case, any problem may occur during the conversion of ammonia in the blood to urea.

An increase in the level of urea in the blood causes the accumulation of urea in both the blood and other organs and causes symptoms specific to these areas. Uremia is usually seen in renal failure. In the case of uremia, especially the digestive system, cardiovascular and central nervous systems are affected.

In patients with uremia, nausea, vomiting, diarrhea and loss of appetite can be seen peculiar to the digestive system. Personality changes may occur if the central nervous system is affected. Irritation, hallucinations and symptoms progressing to coma can be seen in advanced levels of urea.

Since uremia may cause metabolic acidosis, patients may experience Kussmaul breathing, increased skin pigmentation, itching, anemia, and decreased kidney function.

Renal or cardiovascular symptoms can be investigated in patients with suspected increased blood urea level. Especially in patients with signs of kidney failure, the occurrence of symptoms such as inability to urinate or edema in the hands, face and feet draws attention to the blood urea level.

Urea elevation is not evaluated alone, but other tests such as creatinine and kidney functions, the patient’s symptoms, the patient’s disease history and other accompanying diseases are evaluated together.

At the end of long-term follow-up in diabetes patients, a urea test is performed to monitor whether the kidneys are affected. In heart diseases, urea test is performed to examine the kidney functions to be sufficient and the hemodynamic balance of the body.



Before certain drug treatments, if the drugs that are planned to be used are expected to be eliminated from the kidneys, blood urea level can also be checked as a part of kidney function tests.

For urea excretion by the kidneys, it is expected that there will be no disturbances in the blood supply of the kidneys. Congestive heart failure, shock, stress, severe burns, myocardial infarction or conditions that may cause any abnormality in the blood supply of the kidneys may cause an increase in blood urea level.

In cases that prevent the flow of urine from the kidneys itself or at the kidney outlet, the blood urea level may increase, as urinary urea excretion will be hindered.

Conditions that increase blood urea level:

  • Diabetes
  • Obesity
  • Diuretic drugs
  • Cardiac diseases
  • Drinking low water
  • Conditions that cause fluid loss (diarrhea, etc.)
  • Alcohol intake
  • Advanced heart failure
  • Kidney diseases that reduce uric acid excretion
  • Some blood diseases
  • Gout
  • Joint inflammation (arthritis)
  • Kidney stones and diseases
  • Uric acid deposits in bones
  • Excessive protein consumption

Conditions that reduce blood urea level:

  • Liver diseases
  • Nutritional disorders and malnutrition
  • Drinking too much water
  • Diseases that cause urea cycle disorders



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