Prerenal azotemia is common, especially in people who are in the hospital.
The kidneys normally filter the blood. When the volume or pressure of blood flow through the kidney drops, filtering of the blood also drops, or may not occur at all. Waste products stay in the blood and little or no urine is formed, even though the kidney itself is working.
Nitrogen waste products, such as creatinine and urea, build up in the body (azotemia). These waste products act as poisons when they build up. They damage tissues and reduce the ability of the organs to function.
Prerenal azotemia is the most common form of kidney failure in hospitalized patients. Any condition that reduces blood flow to the kidney may cause it, including:
- Conditions that allow fluid to escape from the bloodstream
- Long-term vomiting, diarrhea, or bleeding
- Loss of blood volume (such as with dehydration)
Conditions in which the heart cannot pump enough blood or pumps blood at a low volume also increase the risk for prerenal azotemia. These conditions include:
It also can be caused by conditions that interrupt blood flow to the kidney, such as:
- Certain types of surgery
- Injury to the kidney
- Renal artery embolism
- Renal artery occlusion