Decreased urine output (oliguria)

Oliguria is primarily a symptom for many underlying illnesses and should not be taken lightly. While in most cases the occurrence of such a problem may indicate that the body is recovering from a common illness such as a fever, or simply because not enough liquids have been consumed during the course of a day or a few days, it can be a more serious problem that must be addressed quickly.

As it is often associated with a medical condition, there may be a presence or occurrence of other symptoms associated with the particular underlying condition the person is suspected to have. A person should waste no time in visiting a doctor if their oliguria is accompanied by episodes of dizziness or a rapid pulse rate.

There can be several causes of less than normal urine production. Some of the common reasons include:

• Common illnesses such as fever, diarrhoea and vomiting.
• Dehydration due to the reduced amount of fluid intake.
• Obstruction in the urinary tract: Either an illness causing a blockage in the urinary tract or a physical obstruction may also be responsible for low urine output. An enlarged prostate can lead to such a situation, or the presence of kidney stones can also affect urine production.
• The use of certain medications can also lead to a reduced flow of urine from the body, especially with certain kinds of anti-inflammatory drugs, blood pressure medicines as well as antibiotics.

Some of the more serious causes behind oliguria are as follows:

• Infections: In the case of severe or acute infections, the body may go into shock and be unable to produce its normal amount of urine that it does otherwise.
• Blood loss: Either due to an injury or trauma, the body may lose a lot of blood which may also result in low urine production. (Read more: Bleeding)
• Kidney failure: In acute kidney failure, the body's ability to dispose of waste will be affected, leading to a reduced or no urine output.
• Blood clots: Blood clots in the urinary tract are also associated with this symptom.
• Cancers: Low or no urine output is a symptom of some types of cancer, such as prostate cancer, colon cancer, cervical cancer and bladder cancer.

If the person is young and has no medical history of any serious health condition, then low urine output is most likely due to a common problem like fever, dehydration or just not having enough fluids over the course of a day.

However, low urine output among older adults may point towards something more serious, and the person must visit a doctor without any delay.

The doctor usually performs a physical examination along with asking questions about the person’s medical history, and whether the patient has been having any medications to treat any pre-existing illness.

Information about any symptoms that may be present along with reduced urine output can help the doctor to make an accurate diagnosis—so be sure to share an accurate and comprehensive list of your symptoms with the doctor. 

Issues concerning the urinary tract usually occur with other symptoms such as nausea and vomiting or pain along with fever. However, pain may be present in the case of other illnesses affecting the urine output of the patient as well.

The doctors usually perform a series of tests to be able to diagnose the problem affecting the urine output of a patient. Tests can include a urine test, ultrasounds to look for blockages or masses affecting the flow of urine, as well as CT scans and blood tests.

The treatment of oliguria depends on the condition the patient has been diagnosed with. In the case of dehydration or excess fluid loss from the body, replenishing the body fluids—although in limited, regular amounts—can bring the fluid levels in the body back to normal. (Read more: Oral rehydration salts (ORS) solution: what is it and how to use it)

It is important to understand the cause behind reduced urine output, and seek treatment—the longer one goes without treating the condition, the stronger the effect it has on the functioning of the kidneys.

Severe infections or blood loss due to trauma are treated with a combination of medications as well as putting the patient on an intravenous drip to boost the body's fluid levels and rehydrate it (fluid therapy). This allows the kidneys to continue functioning without going into shock.

Some of the more serious conditions are managed with the recommended treatment for each of those underlying conditions, and the treatment includes restoring the proper functioning of the kidneys.