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.

What Is Perinephric Fat?

By Clara Kedrek
Updated Mar 03, 2024
Our promise to you
The Health Board is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

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.

Editorial Standards

At The Health Board, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Perinephric fat, also known as perirenal fat or the adipose capsule of the kidney, is a layer of fatty material that surrounds the kidneys. It plays an important role because it helps to cushion and protect the kidneys. Evaluation of this layer of tissue can be done either by ultrasonography or computed tomography (CT) scanning. Pathologic processes such as infection and cancers can affect this type of fat.

The human kidneys are surrounded by perinephric fat, which is composed of adipose tissue — a collection of fat cells bound together by connective tissue and supplied by blood vessels. This layer of tissue is found outside of the outer surface of the kidney, but under a layer of connective tissue called the renal fascia. Typically, it is less than 1 inch (2.54 cm) in thickness.

Perhaps the most important function of this fat is to protect the kidneys. Since the kidneys play a critical role in helping the body maintain a consistent internal environment, from filtering out toxins to balancing the concentration of electrolytes within the blood, these organs need to be safe from damage. The perinephric fat, as well as the paranephric fat that is found outside of the renal fascia, helps to cushion and protect the kidneys.

In order to examine this layer of fat, a number of imaging studies can be done. One of the cheapest and most sensitive imaging techniques that can be used to examine this layer of adipose tissue is an ultrasound. This technology uses sound waves to elucidate the structures underlying the external surface of the human body, and is therefore cost-effective and relatively harmless. Computed tomography (CT) scanning, which is typically more expensive and more harmful because it exposes patients to ionizing radiation, can also be performed to investigate this tissue.

A number of conditions can cause abnormalities of this fat layer. One of the most common conditions is pyelonephritis, an infection of the kidneys. The fat can become inflamed as a result of this kidney infection. Alternatively, a severe infection could spread throughout the kidney and cause an abscess to develop within this fat. Patients with an infection this severe can be very sick, and typically require hospitalization and intravenous antibiotics; in some cases the abscesses have to be drained surgically in order for patients to fully recover from their infections.

Another important pathologic process involving the perinephric fat is cancer. A malignancy originating in the kidneys, such as a renal cell carcinoma, can grow and invade into this layer of fat. Knowing whether a cancer has spread into this tissue can have important implications in the treatment and prognosis of a patient with this type of cancer.

The Health Board 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.
Discussion Comments
By Raynbow — On Sep 05, 2014

Most people have never even heard of perinephric fat, unless they are medically trained or have had biology classes. I learned about perinephric fat in college biology, and found it very interested to see how important this type of fat is in protecting the kidneys.

By Heavanet — On Sep 05, 2014

I have a friend who had abnormalities show up in her perinephric fat on a scan, and found out that she had a kidney infection. Though the initial diagnosis scared her because she was afraid the abnormalities would be something more serious, she was fine once she treated her infection.

The Health Board, in your inbox

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

The Health Board, in your inbox

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