Anuria – Definition, Causes, Symptoms, Treatment

Anuria is a condition where there is no urine discharge from the body. The main cause of anuria includes severe kidney problems, hypovolemia, cardiogenic shock and sepsis. The term “anuria” indicates absence of urine. In most cases of anuria patients the urine production would be in very low level. If untreated, anuria can cause death. Kidneys would not stop urine production but would be able to produce in low quantity. The person dies if kidneys stop urine production. Anuria is the worst stage of oliguria wherein the urine production is lesser than 500 ml per day. Oliguria is a strong symptom of kidney malfunction. The patient is left untreated at this stage he/she may develop anuria. In this stage some patients would not have any urine output or lesser than 100 ml per day.

Anuria is a critical condition and the outlook depends on early treatment and the body’s response to it.

Anuria Causes :

Broadly there are 3 major causes of anuria which can be categorized into pre-renal cause, renal cause and post-renal cause.

  • Pre-Renal Causes :

Kidneys are responsible for the production of urine and any problem/disease in the kidneys can affect the urine production. But there are problems outside the kidneys that can lower the urine production. These factors are included in the pre-renal causes. The problem occurring on the areas of blood vessels before it reaches the kidneys are also referred as pre-renal causes.

Some Of The Major Pre-Renal Causes Are Discussed Below :

  1. Hypovelemia conditions like blood leakage (hemorrhage), loss of fluids due to repeated diarrhea and vomiting, burns, diuretics, fluid loss due to operational procedure and pulmonary edema (build up of excess fluid in the lungs) come under this category.
  2. Low systemic vascular resistance can occur due to severe sepsis or shock and severe allergic reactions of certain drugs and intake of antihypertensive drugs.
  3. Heart failure conditions like myocardial infarction, decreased blood supply from the heart, cardiomyopathy, and improper beating of heart fall under this category.
  4. Other causes include pancreatitis, sudden compression of renal vein or inferior vena cava, sudden increase in abdominal pressure, sudden increase of blood sugar levels and potentially life threatening allergic reaction can cause anuria.

Renal Origin :

The problems that occur in the kidneys are grouped as “renal origin”. Presence of glomerulus and renal tubules can drastically reduce urine output causing anuria. Autoimmune diseases, glomerulonephritis, certain kinds of nephrotoxic drugs like amphotericin B, powerful diuretics, ACE inhibitors, kidney diseases acquired by birth (congenital), and hematuria can cause anuria.

  • Post-Renal Causes :

Sometimes, problems may occur after the blood has left the kidneys which are grouped under the head “post-renal causes”. Normal flow of urine can get obstructed due to urinary tract infection and building up of mass in the neck of bladder. Prostatic hypertrophy, stenosis, bilateral ureteral block, problems in the posterior urethral valves and kinks in the catheter can cause anuria.

Symptoms Of Anuria :

  1. The only symptom of anuria is decreased output of urine. Quantity of urine can get reduced gradually and in some cases dribbling of urine can be taken as a sign of anuria. Excess of fluid loss, diarrhea or excess of vomiting are some other symptoms of anuria.
  2. Changes in voiding behavior can be taken as a sign of anuria. If you observe you are not passing normal amount of urine without any obvious causes it can be anuria. One can check the amount of fluid taken in 24 hours and the amount expelled from the body by measurements.

Risk Factors :

People with congenital kidney problems, people with recurrent urinary tract infection and those with enlargement of prostate glands and people who have recently undergone renal surgery are at risk of anuria.


Anuria Tests :

Urine culture can be done for diagnosing anuria. Gravity of urine and presence of any infectious bacteria can be identified by urine culture test.

Anuria Treatment :

Several factors are to be considered before treating patients with anuria. The medical history, period of illness and nature of illness are carefully analyzed. Doctor would evaluate the exact reason for reduced urine output by ruling out any abnormalities. Treatment method is initialized depending on the root cause of the problem. Urine catheterization can be done for removing excess of urine present in the body. The person would pass through the stage of oliguria (very low amounts of urine discharge) before getting into anuria (complete absence of urine).

The health condition of the patient is monitored closely balancing the fluid intake and output. Loads of fluid ingestion is avoided and patient is given only less fluids matching the urine output. It is essential to retain the electrolytic balance to keep the patient stabilized. There are 3 major phases such as phase of oliguria, phase of dieresis and phase of recovery. Diuretic phase starts after a week of oliguria stage wherein the glomerular function begins slowly causing heavy loss of potassium and sodium ions. This is also a crucial stage and fluid loss is carefully monitored. Most of the patients would pass into recovery stage after diuretic stage. Peritoneal dialysis can be done when there is uncontrollable hyperkalaemia (high volumes of potassium in blood). Surgery is done for removing the part that causes obstruction in the normal flow of urine. For those who are not fit for surgery drainage is done internally by using a stent device or externally by nephrostomy.

CPR (Cardiopulmonary Resuscitation) :

  • Cardiopulmonary resuscitation is done for stabilizing the heart rate and blood pressure. Fluids can be removed by resuscitation for increasing the urine output. Central venous pressure should be maintained in normal range of 8-12 mm of mercury with the support of venous catheter.
  • For those who are taking diuretic drugs and nephrotoxic medications, it is advised to discontinue the medications until the urine output becomes normal.
  • For those with urinary tract infection, antibiotics are prescribed for treatment.
  • Infants are at risk of dehydration due to diarrhea and hence health care providers should carefully monitor the condition.

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