What does a reduction of urea in the blood mean?
Urea is a metabolic product that is produced when proteins (proteins and amino acids) are broken down in the body. These are first converted into ammonia, which is toxic to the body, and then broken down into urea in the so-called urea cycle. This can then be excreted via the kidneys.
A decrease in the urea level in the blood is far less significant than an increase. In most cases, the lowered value is due to an insufficient protein intake or an increased protein requirement. Consequently, the lowering of the urea level in the blood is usually harmless.
What symptoms may indicate a decreased urea content?
Since lowered urea levels can have various causes, it is difficult to define specific symptoms for such a level. Symptoms of malnutrition, which is one of the most common causes, include a general feeling of weakness, fatigue, exhaustion, brittle nails and hair. Rarer causes, such as liver damage, are reflected in other symptoms.
These are dominated by a feeling of fullness or pressure in the upper abdomen, skin changes, in extreme cases also ascites, but also exhaustion and tiredness. Other symptoms are caused by a very rare clinical picture that can also lead to lower urea levels: a defect in the urea cycle, the degradation pathway of toxic ammonia. When manifested in adulthood, the symptoms are mainly psychological, but also vomiting, loss of appetite and confusion, and even coma.
In infants, such a defect is usually even more serious. They are lethargic, hardly drink at all and develop seizures that can even lead to death. Since the symptoms are so varied and unspecific, a lowered urea level in the blood is usually discovered rather by chance.
Which diseases lead to a lowered urea level?
As already mentioned, there are not only rather harmless and frequent causes but also rare but more serious reasons for a too low urea value in the blood. The most common cause is a protein deficiency, which can be caused by special low-protein diets or malnutrition, for example. These are usually rather harmless conditions that are easy to remedy.
In addition, athletes, pregnant women and children have an increased protein requirement, which is also reflected in a lower urea value. More rare causes are liver damage, which can be caused by alcohol abuse or viral hepatitis, for example. In the late stages of the disease, the liver is no longer able to convert the ammonia produced in the protein breakdown process into urea.
A defect in one or more enzymes of the urea cycle, the ammonia degradation pathway, has similar effects. Again, the body is unable to convert ammonia into urea. The urea value therefore remains low.
