Azotemia refers to an unusually high amount of nitrogen waste products in the bloodstream. Normally, the kidneys filter blood and expel waste in the form of urine. In the case of azotemia, the kidneys are unable to sufficiently remove urea, creatinine, and other nitrogen-containing compounds from the blood. An individual with the condition might experience fatigue, confusion, high blood pressure, and eventual kidney failure without treatment. Emergency care is often needed to identify and remedy the underlying cause to prevent serious health complications.
Doctors classify azotemia into three general categories, depending on where problems first occur. Prerenal azotemia refers to a complication that decreases blood flow to the kidneys, such as atherosclerosis. Intrarenal azotemia is essentially kidney failure; the problem lies in the kidneys themselves. Postrenal azotemia is the result of an obstruction of urine flow after waste leaves the kidneys. The three types can all lead to dangerous increases in blood urea nitrogen (BUN) and other compounds that are usually expelled in urine.
A person with any of the three types of azotemia may suffer from a rapid heart rate and increased blood pressure. He or she might become confused, fatigued, and lightheaded, and experience decreased urine production. In addition, the skin can turn pale and joints can become inflamed and swollen. Some people experience significant pain and tenderness in the abdomen and lower back. The onset of the condition is often acute, meaning that symptoms come about suddenly, though some cases progressively worsen over the course of several weeks or months.
An individual who believes that he or she has symptoms of azotemia should visit a physician or go to the emergency room as soon as possible. A doctor can conduct a thorough physical examination, ask the patient about symptoms, and collect blood and urine samples for laboratory analysis. Laboratory specialists can confirm a diagnosis by identifying high BUN levels in the blood and low nitrogen levels in the urine. Additional diagnostic imaging tests, such as sonograms, can help the doctor pinpoint the underlying cause of kidney problems.
Patients are often placed in the hospital and given intravenous fluids to reduce the risk of dehydration. If the problem is found to be intrarenal, a dialysis machine can be used to temporarily take over the blood filtration process while kidney problems are assessed. Many patients with prerenal and postrenal problems are able to recover by taking medications to control blood pressure, open constricted blood vessels, and reduce inflammation. Surgery may be necessary if the kidneys shut down completely or a blockage is not resolved with medications.