Staghorn Kidney Stones: What You Need to Know

Staghorn kidney stones are among the most complex and dangerous types of kidney stones due to their unique shape and common association with infections. In this blog, we explore what staghorn stones are, how they form, the risks they pose, how they’re diagnosed, and available treatment options. If you or someone you know has been diagnosed with these branched stones, this information is essential.

Key Takeaways:

• Staghorn kidney stones are defined by their shape, not their composition.
• Most are made from struvite, an infection-based stone linked to UTIs.
• Diagnosis requires urine analysis, checking for pH, infection, and minerals.
• Left untreated, they can cause kidney damage or death.

Staghorn kidney stones are some of the most complex and dangerous stones that can form in the human body. Unlike other kidney stones that are categorized by their chemical makeup, staghorn stones are named for their shape—a branching structure that mimics the internal design of the kidney.

They look like antlers or coral, filling large portions of the kidney's internal space. Because of this, they can severely disrupt kidney function and are often linked to serious infections.

Let’s break down what you need to know about this intimidating type of kidney stone—from their formation to diagnosis, treatment, and prevention.

What Exactly Are Staghorn Kidney Stones?

 Unlike other stones categorized by composition, staghorn kidney stones are defined by their shape.

They form in a way that branches out into the kidney's calyces—the small chambers that collect urine. This “horn-like” design gives the stone its name and makes it uniquely dangerous.

Think of them like a coral reef forming inside your kidney. Because they grow so large and intrusively, they can disrupt the kidney’s filtration ability and reduce glomerular filtration rate (GFR), which is critical to overall kidney function.

Composition: What Are Staghorn Stones Made Of?

The shape doesn’t determine what the stone is made of. These stones can be composed of various materials, but the most common is struvite, a type of infection stone that belongs to the calcium phosphate family.

These stones form when urea-splitting bacteria disrupt the urinary tract environment, creating a breeding ground for struvite crystallization.

This is not something to take lightly. These infection-based stones are found in 49% to 68% of staghorn cases.

Struvite stones can be lethal if untreated. They don’t just impair the kidney—they can lead to complete kidney failure and even death.

Other compositions that may take the staghorn shape include:

• Calcium phosphate stones
• Calcium oxalate stones—both monohydrate (dense) and dihydrate (less dense) types
• Mixed stones—a combination of the above, including struvite, calcium phosphate, and calcium oxalate

The key takeaway? The danger lies in the shape and size—not just the substance.

Why Are They So Dangerous?

Because of their branching design, staghorn stones can invade the deepest pockets of the kidney. They may block urine flow, increase infection risk, and cause permanent damage to kidney tissues.

Patients often experience:

• Decreased kidney function
• Pain or discomfort
• Recurring infections
• Systemic complications if left untreated

When these stones are infection-based (struvite), they become even more aggressive. Untreated infections can lead to sepsis, a life-threatening condition.

This is why early diagnosis and treatment are critical. 

Diagnosing Staghorn Kidney Stones

Diagnosing staghorn stones isn't radically different from other stones, but there are a few extra considerations that are critical to getting it right.

If you suspect you have staghorn kidney stones—or your doctor does—urinalysis is the first major step.

Here’s what that typically includes:

1. Urine pH Testing

The pH level of your urine gives insight into the chemical environment that promotes different stone types.

2. Presence of Infection

Your doctor should check for bacteria in the urine, especially those associated with urea-splitting infections.

Any signs of infection must be taken seriously, as they’re often the root cause of struvite stones and a key reason staghorn stones form in the first place.

3. Mineral Analysis

This includes measuring:

• Calcium
• Oxalate
• Magnesium
• Uric Acid
• Citrate

These help determine what the stone is made of, and how best to prevent future ones.

Don’t be afraid to ask your doctor detailed questions. The more data you have, the more targeted your treatment can be.

Treatment Options for Staghorn Kidney Stones

Because of their size and complexity, staghorn kidney stones usually require medical intervention.

Smaller stones might be passed naturally or broken down using non-invasive techniques, but larger staghorn stones often require surgery or shock wave therapy.

Each treatment depends on the stone’s:

• Size
• Location
• Composition
• Presence of infection

For struvite-based stones, treating the infection is often the first priority. If not managed, the infection will continue to fuel new stone growth.

Can You Prevent Staghorn Stones?

Yes—in many cases, prevention is possible, especially if the underlying causes are addressed.

To prevent staghorn kidney stones:

• Treat urinary tract infections promptly
• Maintain healthy urine pH levels
• Stay hydrated
• Follow up with 24-hour urine testing if you have a history of stones
• Work with a healthcare provider to balance minerals and reduce risk

If your stone was caused by infection, you’ll need to work with your doctor on preventing future infections, which often involves managing gut and bladder bacteria.

Final Thoughts

Staghorn kidney stones are uniquely dangerous due to their complex shape and their common association with infection.

They aren’t just painful—they’re potentially life-threatening. If you or someone you know is dealing with staghorn stones, act fast. Proper diagnosis and treatment are essential to avoid long-term kidney damage.

Don’t ignore the warning signs. These stones are not the kind you can wait out.