The Effect of Less Uptake of Water to the Urea

Proteins and nucleic acids are important molecules that contain nitrogen. When these molecules are broken down, your body produces a nitrogen-containing waste product called urea. Urea is filtered from the bloodstream by the kidneys and expelled from the body through urination.

Significance

• Although your kidneys are very efficient in removing urea and excess salt from the bloodstream, a certain amount of water loss is inevitable. When you feel hot, your body will also try to cool itself by secreting sweat from the glands in your skin. If water lost through sweat, breathing and urination is not replaced, you may eventually begin to suffer from dehydration, a condition where your body has less water than it needs for its normal functions.

Function

• When you become dehydrated, a region of your brain called the hypothalamus increases the amount of anti-diuretic hormone (ADH) in your bloodstream by triggering release of ADH from the pituitary gland. ADH acts on the kidneys to decrease the rate of urine production and to make the urine more concentrated. Since your body no longer has the water it needs to remove the urea from the blood, your blood urea nitrogen (BUN) level begins to rise.

Effects

• While an increased level of urea in the blood is characteristic of dehydration and insufficient fluid uptake, it is not in and of itself life-threatening. It is other possible complications of severe dehydration like organ failure and shock that can eventually cause death.