How to Identify Your Kidney Stone Type

 Understanding how to identify your kidney stone type is critical for choosing the right treatment and preventing future stones. In this blog, I walk you through the three essential methods—density analysis, visual phenotyping, and chemical analysis—and explain how each plays a crucial role. Knowing your stone type could mean the difference between fast recovery and repeated surgeries.

Key Takeaways:

• Identifying your stone type guides better treatment decisions.

• CT scans help reveal stone density, important for treatment planning.

• Visual phenotyping helps uncover root causes behind stone formation.

• Chemical analysis gives exact stone composition, crucial for prevention.

If you suffer from kidney stones, chances are someone has asked you, “What type of stone do you have?”
If you don’t know the answer, you’re missing a crucial piece of the puzzle.

Today, I’m going to walk you through how to identify your kidney stone type and why it’s one of the most important steps you can take.

Why Identifying Your Stone Type Matters

Knowing your kidney stone type isn’t just trivia.
It directly impacts the treatment you choose and your ability to prevent future stones.

Certain stones are incredibly dense, like calcium oxalate monohydrate stones, and treatments like shockwave lithotripsy often don’t work well on them.
Meanwhile, softer stones may break apart easily without needing invasive procedures.

Just as important, every stone type forms for a different reason.
There’s no such thing as a “universal stone former.”
Understanding your stone type helps you uncover root causes, fix them, and stop the endless cycle of stones. 

The Three Main Methods of Kidney Stone Identification

There are three ways to identify your stone type:

• Density-Based Identification

• Visual Phenotyping

• Chemical Analysis

To get the best, most complete picture, you need to use at least two of these methods—especially visual phenotypingcombined with chemical analysis. 

Density-Based Identification: Using CT Scans

When a stone is still inside your body, density analysis is the go-to method.

A CT scan is used to measure something called Hounsfield Units (HU).
This tells us the stone’s density based on how it appears on X-ray images.

Unfortunately, most doctors don’t automatically request density information during a CT scan.
You must ask for it specifically—either by asking for “density” or “attenuation” values.

Here are some common density values:

• Calcium oxalate monohydrate: 879 HU

• Calcium oxalate dihydrate: 517 HU

• Calcium phosphate: 435 HU

• Uric acid: 304 HU

• Cystine: 150 HU

Stones under 750 HU are generally considered weak.
This is important because weaker stones might be passable naturally or breakable with natural supplements.

One limitation:
CT scans can’t detect mixed-composition stones well.
You’ll only get a single density value, even if your stone has multiple layers.

Visual Phenotyping: Seeing Is Believing

Visual phenotyping involves actually looking at the stone to understand its type.

You need either:

• A full, intact stone

• Or good-quality images of passed fragments.

If you’re having surgery, always ask your doctor to save your stone for you!

Visual phenotyping looks at the morphology of the stone:

• Color

• Shape

• Texture

• Surface characteristics

These clues tell powerful stories about why your stone formed.

For example:

• Calcium oxalate monohydrate stones are usually dark, round, and smooth.

• Calcium oxalate dihydrate stones are lighter, more oval, and spiky.

Even though they’re both calcium oxalate stones, they form under slightly different conditions.
This information can point to specific dietary causes or even underlying health conditions like Crohn’s disease.

A Weakness of Visual Phenotyping:
It’s still not great at detecting mixed composition stones, because the surface can hide internal layers. 

Chemical Analysis: The Gold Standard

When it comes to precision, nothing beats chemical analysis.

This method requires fragments or a whole stone.
So again—save your stone!

Labs typically use a technique called Fourier Transform Infrared Spectroscopy (FTIR).

Here’s how it works:

• They clean and dry your stone.

• They grind it into a fine powder.

• They blast it with infrared beams.

The way the stone dust interacts with the light creates a unique fingerprint that can be compared to known stone types.

This method can identify:

• Exact composition percentages

• Mixed stones with multiple materials

• Underlying formation factors

Chemical analysis is the gold standard for uncovering mixed stones.
CT scans and phenotyping might miss these, but chemical analysis will not.

Why You Need Two Methods

Each method has its strengths and weaknesses.
That’s why combining visual phenotyping and chemical analysis gives you the clearest picture.

When you know exactly what your stone is made of and what it looks like, you can:

• Choose smarter treatments

• Identify the root causes

• Create a prevention plan tailored to your body

Final Thoughts: Take Control of Your Kidney Stone Journey

Knowing how to identify your kidney stone type is one of the most empowering steps you can take.

Ask for density information when getting a CT scan.
 

Save your stone if you pass it or have it surgically removed.
 

Order chemical analysis to get exact data.

The more you know, the better you can protect yourself from future stones—and the faster you can get back to living your life without fear.

If you’re ready to start taking control of your kidney stone journey, stick around for more educational blogs and join our community of people reclaiming their health naturally.