Medullary Sponge Kidney and Kidney Stones Explained

Medullary sponge kidney (MSK) is a rare congenital disorder that causes cyst-filled kidneys and frequent kidney stones. Often discovered through imaging, MSK leads to blocked urine flow and acidic imbalances that trigger stone formation. Learn what causes MSK-related stones and what you can do to reduce the pain and frequency of stone attacks.

Key Takeaways:

• MSK creates cysts in the kidneys that resemble Swiss cheese.

• 70% of people with MSK form kidney stones due to urine flow obstruction.

• MSK is often linked to distal renal tubular acidosis, worsening stone risk.

• Hydration, diet, and consistent care can significantly reduce pain and stone formation.

If you've never heard of medullary sponge kidney, this condition can make your kidneys look like Swiss cheese—and it’s as painful as it sounds.

Also known as MSK, this rare disorder doesn’t just distort your kidneys. It also causes frequent kidney stones, often leading to daily discomfort and a lifetime of management challenges.

Let’s break down what MSK really is, why it’s so brutal for stone sufferers, and what you can do to take back control.

What Is Medullary Sponge Kidney (MSK)?

MSK is a congenital disorder, meaning you’re born with it. It affects roughly 1 in every 5,000 people.

Even though the cause remains unknown, it is not always hereditary. The defining trait of MSK is the presence of cysts in the kidney’s medulla, the internal area where urine concentration happens.

These cysts vary in size—from tiny millimeters up to 8 mm, about the size of a dime. On medical imaging, they create dark, porous spots—making the kidney look like a sponge.

That’s where the name comes from.

Symptoms Are Easy to Miss

Many people don’t even realize they have MSK until they get a scan for another issue.

There aren’t distinct symptoms that scream MSK. Instead, signs include:

• Blood in the urine (hematuria)

• Recurrent kidney stones

• Frequent urinary tract infections (UTIs)

Alone, none of these confirm MSK. But together—especially if you’ve had multiple stones—they’re a red flag. Often, it’s discovered during imaging for a kidney stone, not because of a specific MSK test.

Why MSK Causes Kidney Stones

Around 70% of people with MSK form kidney stones.

That’s not a coincidence. There are two main mechanisms that make MSK a stone-forming machine:

1. Decreased Urine Flow
Those cysts in your kidneys restrict how urine moves through your system. This slows things down and leads to two big issues:

• Stone-forming minerals like calcium and phosphate linger too long.

• The longer they stay, the more likely they’ll bind together and form stones.

This is one of the reasons people with MSK suffer chronic kidney pain—the obstructions create intense, ongoing discomfort.

2. Link to Distal Renal Tubular Acidosis (dRTA)
MSK is often tied to another condition: distal renal tubular acidosis.

This condition disrupts how your body manages pH balance, specifically its ability to get rid of hydrogen ions, which are acidic.

When hydrogen ions can’t be properly excreted, several things happen:

• Urine becomes alkaline, which makes it easier for calcium phosphate stones to form

• Urinary citrate levels drop, removing a major line of defense against stone formation

• Urinary calcium increases, from both food absorption and calcium being stripped from bones

Combine all that with the poor urine flow from MSK, and it’s a perfect storm for stone formation.

Managing Life With Medullary Sponge Kidney

If you’ve been diagnosed with MSK—or suspect you have it—you’re not out of options.

There are three key areas to focus on: hydration, diet, and pain management.

1. Hydration: Your First Line of Defense
This might sound basic, but consistent hydration is one of the most powerful tools MSK sufferers have.

Aim for three liters of water per day. But don’t just chug it all at once.

Instead, drink 8–10 ounces per hour while awake. This steady intake does two things:

• Keeps stone-forming minerals from concentrating and clumping

• Reduces pain by preventing your kidneys from stretching unnaturally due to large, infrequent bursts of urine

Avoid what we call “rollercoaster hydration.” Drinking a liter at once and then nothing for hours causes pressure spikes in the kidneys—and those spikes hurt.

2. Diet: Neutralize Your Urine pH
MSK is closely associated with calcium phosphate kidney stones, which thrive in alkaline urine.

That’s why what you eat matters.

Diets high in plants tend to make urine more alkaline. But animal-based or carnivore-style diets can help neutralize urine pH, reducing the risk of calcium phosphate stone formation.

This doesn’t mean everyone needs to go full carnivore. But for MSK patients, shifting toward more species-appropriate foods—lean meats, healthy fats, and possibly a bit of fruit—can make a big difference.

3. Pain Management: Daily Relief Is Possible
Pain is a constant for many with MSK. But it doesn’t have to take over your life.

We created Stone Relief CLEANSE to help with two things:

• Natural pain relief through anti-inflammatory and antispasmodic herbs

• Support for passing existing stones and keeping new ones from forming

For many in the MSK community, taking a low daily dose of CLEANSE has helped reduce both pain and stone recurrence.

Of course, not every product works for everyone, but the right tools combined with hydration and diet give you the best possible shot at improving your quality of life.

Final Thoughts: You’re Not Alone

MSK may be rare, but you’re far from alone. There are entire communities—like the Facebook group I first connected with—full of people just like you, learning how to manage this condition.

Yes, MSK is painful. Yes, it’s frustrating. But you are not powerless.

With the right hydration strategy, a smart diet plan, and the right tools like Stone Relief CLEANSE, you can drastically cut down stone formation and feel more in control.