Azotemia is a medical condition characterized by abnormal levels of urea, creatinine, various body waste compounds, and other nitrogen-rich compounds in the blood as a result of insufficient filtering of the blood by the kidneys.

Uremia can be used as a synonym, or can be used to indicate severe azotemia, in which symptoms are produced.

Azotemia can be classified according to its cause. In prerenal azotemia the blood supply to the kidneys is inadequate. In postrenal azotemia the urinary outflow tract is obstructed. Other forms of azotemia are caused by diseases of the kidneys themselves.

Other causes of azotemia include congestive heart failure, shock, severe burns, prolonged vomiting or diarrhea, or some sort of trauma to the kidney(s).

Signs and symptoms

• Decreased or absent urine output
• Fatigue
• Decreased alertness
• Confusion
• Pale skin color
• Rapid pulse
• Dry mouth
• Thirst, swelling (edema, anasarca)
• Orthostatic blood pressure (rises or falls, significantly depending on position)

A urinalysis will typically show a decreased urine sodium level, a high urine creatinine to serum creatinine level, a high urine urea to serum urea ratio, and concentrated urine (determined by osmolality and specific gravity). None of these is particularly useful in diagnosis.

Prompt treatment of some causes of azotemia can result in restoration of kidney function; delayed treatment may result in permanent loss of renal function. Treatment may include hemodialysis or peritoneal dialysis, medications to increase cardiac output and increase blood pressure, and the treatment of the condition that caused the azotemia to begin with.