Oliguria is when your urine output is lower than what is normal for you. It is usually caused by dehydration and easily treated at home, but can sometimes signify a serious illness requiring timely medical treatment. It’s important to know the symptoms and causes of oliguria—and what can be done about them.*

What are the symptoms of oliguria?

The main symptom of oliguria is decreased urine production. You may notice that:

• You are urinating less frequently and/or have a lighter urine flow.
• Your urine has a darker color than usual, such as amber instead of light yellow.
• Your urine has a reddish color.

In certain cases, suddenly reduced urine output may indicate a serious health issue that requires medical attention. Contact your doctor if your reduced urine output is accompanied by:

• Vomiting 
• Diarrhea  
• Racing heart
• Dizziness or lightheadedness

Untreated oliguria can eventually lead to kidney injury. 

What causes oliguria?

The majority of oliguria cases are caused by dehydration. Dehydration occurs when your body is losing more fluids than it’s taking in. We naturally lose a certain amount of fluids daily through sweat, tears, and basic metabolism, but we lose more than usual through vomiting, diarrhea, intense physical exertion, and spending time in the sun, particularly in hot and/or dry climates. 

Oliguria can also be caused by:

• A physical blockage of or in your urinary tract. Blockages can result from:
  • Kidney stones 
  • Enlarged prostate
  • One or more tumors
  • Injury or congenital abnormality
  • Blood clots
• Medications, such as:
  • Anticholinergics
  • Non-steroidal anti-inflammatory drugs (NSAIDs), like ibuprofen and aspirin 
  • Diuretics, if used excessively or for too long
  • Antibiotics

Other, less common, causes of oliguria can include extreme blood loss, serious infections, shock, and physical trauma.

How is oliguria diagnosed?

Healthcare providers usually diagnose oliguria through:

• Asking you questions about your health, diet, and any pain or discomfort
• Physical examination
• Amount of urine you produce in 24 hours
• Tests that can help determine the cause of your low urine output, including:
  • Urinalysis and urine culture, to check for infection
  • Ultrasound or CT scan of the abdomen, to check for blockages
  • Blood tests, to check electrolyte levels, blood count, and kidney function
  • Cystoscopy (performed with a scope and camera), to test your bladder health

How is oliguria treated? 

Treatments for oliguria are dependent upon:

• Your overall health
• The cause, or likely cause, of your urine decrease
• Whether or not the kidney has been injured 

The most common treatments for oliguria are:

• Increasing your fluid intake, usually from:
  • Water
  • Sports drink containing electrolytes
  • Soups and teas
  • Vegetables and other foods with high water content
• Taking medications, such as:
  • Diuretics, which force your body to produce more urine
  • Antimicrobials, to treat infections
  • Renal-dose dopamine, to expand arteries in your kidneys and increase urine flow
• Stopping medications that may be contributing to the issue

How can I prevent oliguria? 

The best way to avoid the condition is to drink an appropriate amount of fluids daily. The National Academy of Medicine (formerly the Institute of Medicine) suggests an average of 11.4 cups (2.7 liters) of fluids per day for women and 15.6 cups (3.7 liters) per day for men. 

Contrary to popular belief, however, the amount of fluids needed for optimal health is an individual matter that can fluctuate depending on your diet, physical activity, and underlying medical conditions. If you are in mid-to-late-stage kidney disease, for instance, your doctor may not recommend increasing your fluid intake. 

Speak with your healthcare provider to determine what kinds and levels of fluids are best for your health status and situation. 

*Correll, R. (2020, Mar. 31). An Overview of Oliguria. Verywell Health. https://www.verywellhealth.com/oliguria-overview-4783466