We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Health

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Is Fractional Sodium Excretion?

Andrew Kirmayer
By
Updated: May 17, 2024
Views: 6,614
Share

Physicians can monitor the health of the kidneys by comparing the sodium filtered and absorbed to that excreted in urine. Fractional sodium excretion is the calculation of this measurement often used when a kidney disease is suspected. This number can also show what kind of acute renal failure a person has, particularly if the problem is with the blood flow to the kidney or with the organ itself. Sodium in the urine as well as plasma concentrations is typically used in the measurement. These values, along with urinary flow rate, creatinine levels, and the sodium is filtered by the kidney, are often used in calculating the fractional excretion of sodium (FENA).

Fractional sodium excretion is usually determined by a blood test and taking a urine sample. Blood chemistry can be analyzed to detect the salt and creatinine levels, and during the test, the only discomfort is typically the sensation of a needle. The test is usually performed on patients with illnesses that affect kidney function. It can detect if there is a lack of blood flow to the kidneys, in which the FENA will typically be measured at 1% or less. A value of more than 3% often indicates that there is damage to the kidneys.

Illnesses of the circulatory system are typically called prerenal diseases when fractional sodium excretion is measured. If there is kidney damage or failure, acute tubular necrosis can be the cause. An intermediate value can indicate either type of condition, or a blockage in or near the kidneys. Mathematical calculations are done after the blood and urine test results are analyzed. Sometimes the fractional excretion of other substances in urine are measured, such as urea, uric acid, or lithium.

There is typically not much preparation before a fractional sodium excretion test. Doctor’s often suggest avoiding diuretics because they can alter the absorption of sodium in the kidneys, as well as other medications that can do so. The testing is generally low risk, while complications from blood tests can include bleeding, fainting, or infection in some cases.

Conditions that can be detected from fractional sodium excretion include cirrhosis of the liver or congestive heart failure. Kidney conditions such as acute glomerulonephritis, renal failure, or rhabdomyolysis can be associated with a low FENA count. The number can be high if a person vomited or is being treated with a nasogastric tube for suctioning, as biological processes can prevent the re-absorption of sodium.

Share
WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Andrew Kirmayer
By Andrew Kirmayer
Andrew Kirmayer, a freelance writer with his own online writing business, creates engaging content across various industries and disciplines. With a degree in Creative Writing, he is skilled at writing compelling articles, blogs, press releases, website content, web copy, and more, all with the goal of making the web a more informative and engaging place for all audiences.

Editors' Picks

Discussion Comments
Andrew Kirmayer
Andrew Kirmayer
Andrew Kirmayer, a freelance writer with his own online writing business, creates engaging content across various...
Learn more
Share
https://www.wisegeek.net/what-is-fractional-sodium-excretion.htm
Copy this link
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.