Anuria – Why it Happens and What To Do About It?

The media has done much to publicize health issues such as urine leakage or incontinence.

But what is less well known is the condition called anuria. Anuria occurs when urine output falls dangerously low.

The technical, medical definition for the term anuria is “absence of urine.” But according to iHealth Blogger, anuria does not mean urine output fails to occur.(1)

It means the kidneys begin to produce much less urine, typically less than 100 mL per day (less than half a cup!) for adults.

There are many possible reasons why anuria might begin to occur.

If you or someone you love may be suffering from this health issue, it is important to learn everything you can about the condition so you can receive an accurate diagnosis and begin treatment as soon as possible.

In this article, learn more about what anuria is, what causes it, the warning signs and symptoms, how anuria is diagnosed and treated and what to do next if you think you may have this condition.


What Is Anuria?

In most cases, the initial presentation of anuria begins with another similar condition called oliguria. According to eMedicine Medscape, oliguria refers to a reduced urine output of less than 400 mL per day (about 1.7 cups) for adults.(2)

Anuria and oliguria can happen to someone of any age, even as early as infancy. As you might imagine, the output is greatly reduced for either condition in a child or infant.

For infants, the output level required to qualify for oliguria is 1 mL in infants (.004 cups) and 0.5 mL in children (.002 cups).

Birmingham Children’s Hospital states that for infants, the absence of urine output beyond the first 24 hours is a qualifying symptom for anuria.(3) For children, the output of less than 1 mL (.004) cups is a pre-qualification for diagnosis.



What is most important to understand about this condition is what proper daily urine output should be in order for the body to stay in good health.

According to Doctors Health Press, daily urine output should fall between 300 and 500 mL (1.3 to 2.11 cups) per day to ensure the body is adequately ridding itself of waste in the form of urea.(4)

In most cases, oliguria will present first, meaning that the healthcare team is already monitoring for advancement to anuria. But sometimes it is not caught in the oliguria stage, which means anuria will be the initial diagnosis.

When anuria occurs, the first and most likely cause is a renal (kidney) failure. Renal failure can occur due to a malfunction at any stage in the kidney function process as follows:


When anuria occurs as a result of a malfunction in the pre-renal stage, the kidneys are implicated only indirectly.

There are three main known reasons why pre-renal anuria might occur as follows:

Hypovolemia. When blood plasma levels decrease, this may be due to a systemic fluid loss such as that caused by ongoing diarrhea or vomiting, surgical fluid loss, an overdose of diuretics, pulmonary edema (fluid around the heart), blood hemorrhage or serious burns.

Expanded blood vessels. Known formally as “low vascular resistance,” when the blood vessels begin to expand, blood pressure can drop dangerously low. Systemic shock, sepsis or side effects from medications can cause this condition.

Heart failure. Many other health issues can lead to heart failure, such as heart arrhythmia (erratic heartbeat), stroke, heart attack and low blood output.

However, these are just the three most common reasons for pre-renal anuria. Advanced diabetes, pancreatitis and use of some medicines while pregnant have also been implicated.


Ongoing disease or medication use can cause failure within the kidney system itself. Including autoimmune diseases and acquired diseases, congenital renal issues can also cause anuria in the renal system.


One of the kidneys’ main jobs is to facilitate blood filtration to extract waste matter from the blood that is converted into urea and excreted out of the body in the form of urine.

When the kidneys are functioning properly, up to 150 quarts of blood will pass through the kidneys daily for filtration.(5) In this case, daily urine output should be between one and two quarts.

When the kidneys cease producing healthy quantities of urine, there could be a number of possible causes. One of the major causes is a blockage, which may be caused by an obstruction (such as an adhesion, or scar tissue, from prior surgery or trauma to the area) or blockage (such as from a tumor or benign mass).

A malfunction in the urinary tract or prostate gland may also be a possible cause.



Hows Health reports that anuria is actually considered a symptom of a more serious underlying condition.(6) However, anuria can also produce symptoms to varying degrees depending on that underlying cause and how long it has gone undiagnosed.

According to HPathy, some of the most commonly reported patient symptoms include these:(7)

» Symptoms beginning with mild urine incontinence.
» Absence of or greatly reduced urine output.
» Persistent sense of bladder urgency with no output.
» Diarrhea.
» Loss of appetite.
» Previous history of recurring UTI (urinary tract infection).
» Swollen renal glands or prostate gland.
» Edema in other areas of the body.
» Nausea.
» Fever and chills.
» Low abdominal pain.
» Vomiting.
» A headache.
» Fatigue or drowsiness.
» Muscle twitching.
» Swollen or painful joints.
» Skin rash.
» Increased fluid intake with no increase in urine output.

Depending on the underlying cause of the anuria, other symptoms may be present as well.

For this reason, it is very important to take detailed written notes about your symptoms, including how long they have been going on and when they occur. This can help your doctor narrow down possible causes more rapidly so you can be treated right away.

Prompt treatment is an urgent need when anuria is present. The ongoing lack of urine output without treatment can be and sometimes is fatal.


How Is Diagnosed

According to Red Urine, the initial diagnostic stage begins with your doctor taking a thorough individual and family medical history.(8) Of particular importance here will be any family history of renal or prostate problems.

You should also be prepared to provide a full list of all medications and supplements, including any over-the-counter medications (such as diuretics) or recreational drugs/alcohol use. If you have been keeping a symptoms log, you should bring this with you to your appointment as well.

You will likely be asked to estimate the amount of liquid you drink daily and whether drinking more produces any increase in urine output.

As Healthline states, obtaining a urine sample can be an important part of the diagnostic process.(9) However, when a diagnosis of anuria is suspected, this may be difficult to achieve.

If it is possible for you to produce a urine sample (called a urine swab or urine culture), your doctor will order tests to determine levels of uric acid, overall color (pale to bright), proteins present and infection markers.

Even if you are able to give a urine sample, for diagnostic confirmation these other tests are also frequently performed:

Blood CBC (complete blood count and blood chemistry). This test analyzes your blood for the presence of disease or infection markers and overall composition.

Abdominal imaging. This test uses ultrasound technology to look at your abdomen and kidneys to examine for possible obstructions or blockages, including tumors.

CT scans with cardiac or renal focus. Another possible test that may be ordered is a CT scan with a cardiac or renal focus. This test can look at body systems in detail to note fluid buildup, swellings, growths, blockages and other issues that may be implicated in anuria.



It nearly goes without saying that treating anuria is of the utmost urgency.

The longer waste products build up inside your body, the more severe your symptoms will become. For this reason, it is vital not to put off seeking professional medical attention (i.e. to date, there is no known non-medical self-treatment available for anuria).

The treatment phase often begins with hospitalization and an I.V. drip. This is done to rehydrate your body in cases where renal failure is not considered to be the primary underlying cause. In cases where kidney failure is suspected or confirmed, dialysis is the preferred first step so the toxins can be promptly removed from your system.

Once you are stabilized via re-hydration and detoxification, your doctor may place a urine catheter to bypass any blockage or obstruction that may be impeding or preventing urine flow. If your system is very weak, it is often necessary to tend to re-hydration, detoxification and catheterization before proceeding forward with any longer-term treatment.

Surgery is often prescribed for blockages or obstructions. For patients experiencing anuria due to medication side effects, the medication is often discontinued or changed. Patients with anuria stemming from UTIs will be treated with antibiotics.

Throughout, fluid intake and urine output along with electrolyte levels will be closely monitored.



If you, or someone you care about, seems to be displaying symptoms of this condition, it is important to seek medical care right away by following these steps:

» Keep a detailed written symptoms log.
» Make an appointment with your doctor.
» Promptly have all recommended tests performed and receive the results.
» Achieve an accurate diagnosis of anuria and proceed to the treatment phase.
» Follow all treatment recommendations as outlined by your doctor.