Because each patient has his own body fluid volume, it is not reasonable to examine a patient only by solute concentration In this paper, we calculated total body fluid using urea as a marker, called urea space (US), by four different kinetic models. Each result, calculated by those four equations, is puite agreed. So we concluded that the urea behavior in a body was explained by single-pool model. Hypertension patients were high in UBR (US-Body weight Ratio), and hypotension were low. UBR may be one step to evaluate the symptom of blood pressure depended upon salt and water.
