How Do You Get A Kidney Stone And Can You Prevent It?

Kidney stones form when certain minerals and salts in urine become concentrated enough to crystallize. The most common type, calcium oxalate, develops when urine is low in volume or high in stone-forming substances while lacking enough of the compounds that normally keep crystals from clumping together. Whether you can prevent them depends on the type of stone, but the single most consistent finding across decades of research is simple: drinking more water reduces recurrence.

What Exactly Is a Kidney Stone?

A kidney stone is a hard, solid mass built from minerals and acid salts that normally pass through urine without issue. When the balance of water and dissolved particles shifts, those particles can bind together and grow into a crystal that becomes a stone.

Stones range from the size of a grain of sand to the size of a golf ball. Small ones often pass on their own. Larger ones can block the flow of urine and cause severe pain.

There are four main types, and each forms for different reasons:

• Calcium oxalate — the most common type, accounting for the majority of stones
• Calcium phosphate — often linked to certain metabolic conditions
• Uric acid — associated with low urine pH and gout
• Struvite — typically caused by urinary tract infections

Knowing which type you have matters. Prevention strategies that work for one type may not help with another. A stone that is analyzed in a lab tells your doctor far more than a guess based on symptoms.

How Do You Get a Kidney Stone?

Stones form when urine becomes supersaturated — meaning it holds more dissolved mineral than it can keep in solution. At that point, crystals begin to form. Whether those crystals grow into a full stone depends on several factors working together.

Low urine volume is the biggest single contributor. When you do not drink enough fluid, urine becomes concentrated, and the concentration of stone-forming minerals rises. This is why people in hot climates and those who work outdoors in the heat tend to have higher rates of stones.

Diet plays a role too, but not always in the way people expect. Eating too much sodium increases calcium in the urine, which raises calcium stone risk. Getting too little calcium from food is also a problem — dietary calcium binds oxalate in the gut before it can be absorbed, so restricting calcium can actually raise oxalate levels and increase stone risk. This is one of the most counterintuitive findings in kidney stone research.

Other established contributors include:

• Obesity and insulin resistance
• Gout, which raises uric acid levels
• Certain medications, including some diuretics and calcium supplements taken without food
• Recurrent urinary tract infections
• Family history of stones
• Digestive conditions like Crohn’s disease or prior bariatric surgery, which change how the gut absorbs oxalate

Some people have a genetic tendency to excrete more calcium or oxalate in their urine. For these individuals, diet alone may not fully explain why stones keep forming.

What Are the Symptoms of a Kidney Stone?

The classic symptom is severe, cramping pain that starts in the lower back or side and may radiate toward the groin. It often comes in waves as the stone moves and the ureter — the tube connecting the kidney to the bladder — contracts against it.

Other common symptoms include:

• Blood in the urine, which may be pink, red, or brown
• Nausea and vomiting
• Pain or burning during urination
• Urgent or frequent need to urinate
• Fever and chills, which may indicate infection

Fever with a kidney stone is a medical emergency. It can signal an infected, blocked urinary tract, which requires immediate care.

Not everyone feels pain right away. Some stones sit quietly in the kidney for years and are found only during imaging for another reason.

Can You Prevent Kidney Stones?

Yes, for many people. Prevention works best when it targets the specific type of stone and the underlying cause. The general strategies below apply to most stone formers, but your doctor may adjust them based on your stone analysis and urine testing.

Drink More Water

Increasing fluid intake is the most reliable way to reduce stone recurrence. The goal is to produce enough urine to keep minerals diluted. A common clinical target is about 2.5 liters of urine per day, which usually means drinking somewhere in the range of 2.5 to 3 liters of fluid daily for many adults. People who sweat heavily may need more.

Water is the best choice. Some research suggests that citrus drinks like lemonade or orange juice may help because citrate inhibits calcium stone formation, but the evidence is not strong enough to recommend them as a primary strategy.

Watch Your Sodium

High sodium intake increases calcium in the urine. Reducing sodium is one of the more effective dietary changes for calcium stone formers. Most dietary sodium comes from processed foods, not the salt shaker.

Get Enough Calcium From Food

This is where many people get it wrong. Unless your doctor tells you otherwise, do not cut calcium from your diet to prevent stones. Dietary calcium binds oxalate in the digestive tract and reduces how much reaches the kidneys. The evidence supports normal dietary calcium intake for most stone formers. Calcium supplements are a different story — they may raise stone risk if taken without food, and some clinicians recommend taking them with meals if they are needed at all.

Limit Oxalate-Rich Foods — Selectively

Not everyone needs to restrict oxalate. For people who form calcium oxalate stones and have high urinary oxalate, limiting foods like spinach, rhubarb, beets, and nuts may help. Boiling these foods and discarding the water reduces their oxalate content. For others, broad oxalate restriction is unnecessary and can make it harder to eat a balanced diet.

Reduce Animal Protein

Large amounts of animal protein can lower urine pH and reduce citrate, both of which promote stone formation. Moderating meat intake may help, particularly for uric acid stone formers.

Which Foods and Drinks Affect Stone Risk?

Diet influences stone risk, but the effects vary by stone type and by individual. Here is what the evidence generally supports:

No single food causes stones on its own. It is the overall pattern of fluid intake, mineral balance, and individual susceptibility that matters most.

When Should You See a Doctor?

See a doctor if you have pain severe enough to interfere with daily life, blood in your urine, fever, or vomiting that prevents you from keeping fluids down. Fever with flank pain needs urgent care.

If you have had one stone, your risk of another is significant. Some studies suggest that without prevention, roughly half of people who form one stone will form another within five to ten years. This is why stone analysis and a metabolic workup are worth discussing with your doctor after a first stone.

Prevention is not one-size-fits-all. A urine collection test can show whether you excrete too much calcium, oxalate, uric acid, or too little citrate. That information guides treatment far better than general advice alone.