What the Renal Columns Do Inside the Kidneys

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What the Renal Columns Do Inside the Kidneys

By Your Health Magazine Health Information Team

If an ultrasound or CT report mentions a “prominent renal column” or “column of Bertin,” it is understandable to wonder whether something is wrong with your kidney. The reassuring answer is that renal columns are normal parts of kidney anatomy. They are not growths, stones, or separate organs. Their location and appearance help the kidneys maintain an organized internal structure while supporting blood flow and the work of nearby filtering tissue.

What Is the Function of the Renal Column?

The main function of the renal column is to extend kidney cortex tissue inward between the renal pyramids. These columns separate neighboring pyramids, help define the kidney’s internal lobes, and provide pathways for blood vessels traveling through the organ.

Renal columns do not perform one isolated task in the way that a heart valve or a ureter does. Instead, they are continuous with the renal cortex, the outer region of the kidney where important parts of the nephrons are located. Nephrons are microscopic structures that filter blood and help regulate water, electrolytes, acids, and waste products.

Because renal columns are made of cortical tissue, they contribute to the overall organization and function of the kidney. However, it is more accurate to think of them as integrated structural and vascular regions rather than independent filtering units.

Where Renal Columns Fit Within Kidney Anatomy

Each kidney has an outer cortex and an inner medulla. The medulla contains cone-shaped areas called renal pyramids. Urine-making tubules pass through these pyramids and eventually deliver urine through the papillae at their tips into small collecting spaces called calyces.

The renal cortex covers the outside of the kidney but also dips inward between the pyramids. These inward extensions are the renal columns, also known as the columns of Bertin. They are sometimes described as cortical septa, although they are not hard or sealed walls. They are living kidney tissue containing blood vessels, tubules, and supporting material.

Together, a renal pyramid and the cortical tissue associated with it form a renal lobe. By lying between the pyramids, renal columns help maintain this lobed arrangement inside the kidney.

How Renal Columns Support Blood Flow

The kidneys need a substantial and carefully organized blood supply because filtration begins with blood entering microscopic clusters of capillaries called glomeruli. The renal artery enters the kidney and divides into progressively smaller branches.

Interlobar arteries and veins travel between the renal pyramids through the renal columns. Near the bases of the pyramids, these vessels connect with arcuate vessels that curve along the border between the cortex and medulla. Smaller branches then extend into cortical tissue and supply the nephrons.

This means that an important function of the renal column is providing an anatomical route for vessels carrying blood toward and away from filtering regions. The columns do not pump blood, but their placement helps organize the vascular network needed for normal kidney activity.

Do Renal Columns Make Urine?

Renal columns participate in kidney function because they are made of cortical tissue, but they should not be confused with the kidney’s collecting system. Urine production occurs through coordinated work across the nephrons. Blood is filtered in the glomeruli, useful substances and water are reabsorbed along renal tubules, and additional wastes may be secreted into the tubular fluid.

The resulting urine moves through collecting ducts in the renal pyramids before entering the calyces, renal pelvis, ureters, and bladder. In other words, renal columns help support and organize the tissues involved in this process, while the pyramids and collecting system provide much of the route through which finished urine drains.

Why a Renal Column May Be Mentioned on an Imaging Report

Most people never hear about their renal columns unless they have an ultrasound, CT scan, or MRI. In some individuals, one column is wider or more noticeable than the others. This may be called a prominent or hypertrophied column of Bertin.

A hypertrophied renal column is generally a benign anatomical variation. Because it may bulge toward the renal sinus, it can occasionally resemble a mass on an initial ultrasound. Radiologists evaluate whether the area remains continuous with the surrounding cortex and whether its texture, blood flow, density, and contrast-enhancement pattern match normal kidney tissue.

A report recommending additional imaging does not automatically mean cancer is suspected or present. It may simply mean the clinician wants a clearer view before confirming that the finding represents normal cortical tissue. A prominent column should be interpreted by the radiologist in the context of the complete examination rather than diagnosed from a single phrase in a report.

Can Renal Columns Become Diseased?

There is not usually a separate “renal column disease.” Because the columns consist of renal cortical tissue and contain blood vessels, conditions affecting the kidney cortex, circulation, or surrounding structures may also involve them. Kidney infections, inflammation, reduced blood flow, scarring, cysts, or tumors can alter the appearance of kidney tissue, but symptoms and test results typically reflect the broader condition rather than a problem limited to one column.

Kidney disorders may produce few symptoms in their early stages. When evaluation is needed, clinicians commonly use blood pressure measurements, blood tests, urine tests, and imaging. A renal function panel and related kidney testing can provide information about filtration, electrolyte balance, and waste removal. Depending on the concern, urine testing may also look for blood, protein, infection, or other abnormalities.

How Kidney Structure Affects Everyday Health

You will not feel your renal columns doing their job. Their contribution is part of the kidneys’ continuous work of removing wastes, adjusting fluid and electrolyte levels, supporting acid-base balance, helping regulate blood pressure, activating vitamin D, and producing signals involved in red blood cell formation.

A normal variation in renal column size generally does not affect urination, energy level, diet, exercise, or daily activity. If kidney function is abnormal, the underlying disease or injury—not the mere presence of renal columns—is what requires medical attention. For an overview of kidney conditions and testing, see this information about kidney diseases and renal health.

When to Seek Care

Contact a primary care clinician if you develop persistent changes in urination, blood in the urine, unusually foamy urine, swelling around the eyes or in the legs and ankles, ongoing fatigue, or unexplained changes in blood pressure. Flank or back pain accompanied by fever, chills, nausea, vomiting, or painful urination may require prompt evaluation for infection or obstruction.

Seek urgent medical care for severe flank pain, an inability to urinate, markedly reduced urine output, significant blood in the urine, or symptoms following an injury to the back or abdomen. A primary care professional can begin the evaluation. A nephrologist treats medical kidney disorders, while a urologist commonly evaluates structural problems, urinary obstruction, stones, and certain kidney masses.

The Bottom Line

The function of the renal column is primarily structural and supportive. Renal columns are inward extensions of the kidney cortex that separate the renal pyramids, help organize renal lobes, and carry important blood vessels through the kidney. They are normal anatomy, and a prominent column of Bertin is often simply a benign variation. If the term appears in an imaging report, review the complete findings with the clinician who ordered the test so the description can be understood in the proper medical context.