Urination is a vital process and the result of the kidneys filtering and removing waste products, fluids, electrolytes, and other substances the body no longer wants or needs.
The substances that are waiting to be expelled back up in the body and are not removed if the kidneys cease working and urination stops. This blockage can cause other health problems and be life-threatening if not treated.
Anuria is diagnosed when the kidneys are producing less than 500 milliliters (mL) of urine each day. A usual daily urine output is between 1 to 2 liters for an adult.
What are the causes of anuria?
Anuria occurs when the kidneys stop producing urine.
Anuria is mostly caused by problems in the kidneys, but it can also result from problems in the heart.
Some of the causes of anuria include:
- Diabetes: When a person's blood sugar is consistently high, such as with uncontrolled diabetes, it can result in diabetic ketoacidosis, and damage to the small blood vessels in the kidneys. This can cause acute renal failure and poor or absent urine production.
- Kidney stones: These stones can cause blockages in the kidneys or ureters, the tubes that transport urine from the kidneys to the urethra where it is passed out of the body. These blockages mean the urine is unable to exit the body.
- Kidney failure: Acute kidney failure occurs when the kidneys stop functioning and are unable to filter urine anymore.
- High blood pressure: Also known as hypertension, high blood pressure can damage the blood vessels in the kidneys over time. Without treatment, high blood pressure can lead to permanent kidney damage and anuria.
- Tumors: A growth on or near the kidney can cause a blockage and keep urine from passing out of the body.
- Heart failure: When a person has heart failure the heart cannot pump enough blood around the body. Processes in the body kick in if there is not enough fluid in the blood vessels. One of these is the kidneys ceasing to make urine to hold on to extra fluid.
Signs and symptoms
Anuria or not urinating is a symptom itself and not a medical condition. Sometimes, a person may also have signs of the condition that is causing the poor urine output.
The symptoms of kidney disease can include:
- swelling in the legs, feet, ankles, face
- rash or itching of the skin
- flank pain in the back or side
- nausea or vomiting
- shortness of breath
- difficulty concentrating
Symptoms of heart failure can include:
- shortness of breath
- swelling of the legs
- fatigue or dizziness
- poor appetite
- high heart rate
- coughing or wheezing
Symptoms of diabetic ketoacidosis include:
- excessive thirst
- dry mouth
- abdominal pain
- loss of appetite
- fruity odor on the breath
Anyone experiencing any of these signs or symptoms, or who has stopped urinating, should see their doctor immediately, or proceed to the nearest urgent care or emergency room.
How is anuria diagnosed?
To help diagnose anuria a doctor may request a urine sample to check for blood or sugar in the urine.
Diagnosing anuria and its underlying cause starts with a thorough medical history and interview when a doctor will ask about the person's medical history and medication use.
The doctor will also ask about symptoms and changes in urination, including:
- changes in appetite
- blood in the urine
- frequency of urination
- quantity of urine passed
- abdominal or flank pain
The doctor may suggest additional testing, such as blood testing for kidney function, urine testing for blood or sugar, a biopsy of the kidney or imaging tests, including X-rays, CT scans or MRI scans.
Hospitalization may be needed until a person's kidney function has been restored or the cause of the anuria is determined.
If urine output cannot be restored, it can be life-threatening. The condition causing the anuria can also be very dangerous.
The primary complication of anuria is kidney damage or failure. This can be permanent and can cause someone to need dialysis or a kidney transplant.
Anuria can be fatal if not treated, so prompt treatment is vital if someone suspects anuria.
What are the treatment options?
If anuria is a sign of an underlying condition, treatment depends on what that underlying condition might be.
It is important for those with diabetes to monitor their blood sugar.
People with diabetes should be careful to control their blood sugar levels. It is important to monitor blood sugar as directed, follow the prescribed diet and exercise regimen, and to take all medication, as directed.
Regularly following up with the doctor can also help to identify quickly when changes need to be made, and it can minimize the risk of complications.
Making positive lifestyle changes is also very important for someone with high blood pressure. The doctor should recommend diet and exercise changes and may suggest medication to help keep blood pressure low. Stress relief and getting enough sleep are also necessary.
Removing kidney stones or tumors
Someone with an obstruction in the kidneys, such as from a kidney stone or tumor, will need to have it removed. This may mean surgery, medication chemotherapy, or radiation therapy to shrink or remove the tumor or stone.
Kidney disease management
Kidney disease is treated with dialysis, which is a procedure that removes excess fluid, electrolytes, and waste products from the blood. Dialysis is performed in an outpatient clinic, or the hospital if needed, 3 to 4 times a week.
There are several ways to have dialysis. Normally, the blood is removed, passed through a special filter to take out the waste products, and then reinfused back into the body.
Someone with kidney damage and who is on dialysis may be a candidate for a kidney transplant. Not everyone is a candidate for this type of surgery because of the risks and long-term care necessary afterward.
The outlook for someone with anuria depends on several factors, including its underlying cause, how quickly it is diagnosed and treated, and the person's overall health and wellness.
Because of the potential severity of anuria and the conditions associated with it, it is best to see the doctor as quickly as possible if there are any changes in urine output.