Understanding Kidney Stones: Causes, Types, Symptoms & Treatment Options

What is kidney Stone

Kidney stones, also known as renal calculi, nephrolithiasis, or urolithiasis, are hard deposits made of minerals and salts that form inside the kidneys. These solid masses can range in size from a tiny grain of sand to as large as a golf ball. Kidney stones develop when substances such as calcium, oxalate, urate, cystine, xanthine, and phosphate crystallize in the urine, form solid deposits. It typically occurs when there is an excess of waste and too little liquid in the urine, leading to the crystallization of these substances. After it is formed, the stone may stay in the kidney or travel down the urinary tract into the ureter.

The word nephrolithiasis comes from “nephro,” which means kidney in latin, and “lithiasis,” which is a medical term for stones.

Kidney stones can form anywhere in the urinary tract, including the kidneys, ureters, bladder, and urethra. Small stones may pass through the urinary system unnoticed, while larger stones can become lodged in the ureter, causing pain and obstructing urine flow. This blockage can lead to complications such as kidney infections and impaired kidney function.
The presence of kidney stones is often associated with severe pain, particularly when passing through the urinary tract. In most cases, small kidney stones can pass naturally through increased fluid intake and pain management. However, in cases where stones become lodged, are associated with urinary infections, or cause complications, surgical intervention may be necessary.

Risk factors for kidney Stones

Several factors can increase the risk of developing kidney stones. A family or personal history of kidney stones is a significant risk factor, as individuals with a history of stones are more likely to develop them again. Dehydration is another major contributor; inadequate water intake leads to concentrated urine, which promotes stone formation. People living in hot, dry climates or those who sweat excessively are at a higher risk.

Having a blockage in your urinary tract.

Certain medications such as diuretics, calcium-based antacids, some antiseizure medications

Certain health conditions increases risk and includes:

• Cystic fibrosis.
• Diabetes.
• GoutKidney cysts.
• Osteoporosis.
• Parathyroid disease.
• High blood pressure.
• High calcium levels in your urine (hypercalciuria).
• Inflammatory bowel disease (IBD).

Causes of kidney Stones

Kidney stones develop due to a combination of genetic predisposition, dietary habits, dehydration, medical conditions, and certain medications. Understanding these factors can help individuals take preventive measures to reduce their risk of developing kidney stones.

Dehydration is one of the most common causes of kidney stones. Insufficient fluid intake leads to concentrated urine, which increases the likelihood of mineral crystallization and stone formation. People who live in warm climates, engage in excessive sweating, or do not drink enough water are particularly at risk.

Diet plays a critical role in kidney stone formation. Consuming certain foods in excess can increase the likelihood of developing stones. Key dietary contributors include:

• High sodium intake:Increased sodium levels in the diet raise calcium levels in urine, which can contribute to calcium-based stones.
• High oxalate foods:Foods such as spinach, nuts, and chocolate contain high oxalate levels, which can combine with calcium to form calcium oxalate stones.
• High-protein diets:Excess consumption of animal proteins (red meat, poultry, eggs, and seafood) raises uric acid levels, leading to uric acid stone formation.
• Excess sugar intake:High fructose and processed sugars contribute to an increased risk of kidney stones.

Certain medical conditions increase the likelihood of kidney stone formation, including:

• Diabetes and obesity:Increased urine acidity in individuals with metabolic syndrome or diabetesraises the risk of uric acid stones
• Hyperparathyroidism:This condition results in excess calcium in the blood and urine, increasing the risk of calcium-based stones
• Renal tubular acidosis:This kidney disorderaffects acid removal from the blood, leading to calcium phosphate stones
• Inflammatory bowel disease (IBD):Crohn’s disease and ulcerative colitis can affect calcium and oxalate absorption, contributing to stone formation
• Recurrent urinary tract infections (UTIs):Chronic UTIs can lead to struvite stones, which grow quickly and may require surgical removal
• Cystinuria:A hereditary disorder causing excessive cystine excretion in urine, leading to cystine stones

Certain medications and supplements contribute to kidney stone development, including:

• Excess vitamin C intake
• Calcium-based antacids
• Diuretics
• Migraine and seizure medications

Types of Kidney Stones

Kidney stones can be classified into several types based on their named composition. The main types include:

Calcium Stones

Calcium stones are the most common type of kidney stone, typically composed of calcium oxalate. Oxalate is a naturally occurring substance produced by the liver and absorbed from dietary sources, including certain fruits, vegetables, nuts, and chocolate. Factors such as high dietary oxalate intake, excessive vitamin D supplementation, intestinal bypass surgery, and metabolic disorders can elevate calcium or oxalate concentrations in urine, increasing the likelihood of stone formation.
Calcium phosphate stones are another form of calcium-based kidney stones. These stones are more commonly associated with metabolic conditions such as renal tubular acidosis. Additionally, certain medications used to treat migraines or seizures, including topiramate (Topamax, Trokendi XR, Qudexy XR), may contribute to calcium phosphate stone formation.

Struvite Stones

Struvite stones develop in response to urinary tract infections(UTIs). These stones can grow rapidly and become quite large, sometimes with minimal symptoms or little warning. Struvite stones are more common in individuals who experience recurrent bacterial infections in the urinary tract.

Uric Acid Stones

Uric acid stones can form in individuals who lose excessive fluid due to chronic diarrhea or malabsorption, consume a high-protein diet, or have conditions such as diabetesor metabolic syndrome. A genetic predisposition may also contribute to the development of uric acid stones. These stones form when urine becomes excessively acidic, often due to a diet rich in purine-containing foods, such as red meat, shellfish, and organ meats.

Cystine Stones

Cystine stones occur in individuals with a hereditary disorder known as cystinuria, a condition that leads to excessive excretion of cystine, an amino acid, into the urine. This rare type of kidney stone affects both men and women and often results in recurring stone formation throughout life.

Signs & Symptoms of kidney Stones

Kidney stones may not cause noticeable symptoms until they begin to move within the kidney or pass into the ureter. When a stone becomes lodged in the ureter, it can obstruct urine flow, leading to severe pain and other symptoms.

• Pain while urinating
• Frequent urge to urinate
• Blood in the urine
• Cloudy or foul-smelling urine
• Inability to urinate
• Nausea and vomiting
• Fever and chills
• Severe, sharp pain typically occurs in the side and back, just below the ribs
• Radiating pain that spread to the lower abdomen and groin
• Waves of pain - intensity of the pain fluctuates, often coming in waves

Diagnostic Tests & Investigations

Suspected kidney stone based on the symptoms and physical exam, the may need one or more of these tests:

• Urine test
• Urinalysis
• Abdominal CT scans
• Ultrasound
• Blood tests for calcium, phosphorus, uric acid, and electrolytes
• Blood urea nitrogen (BUN) and creatinine to assess kidney functioning
• Abdominal X-rays
• Intravenous pyelogram (IVP)
• Retrograde pyelogram
• MRI scan of the abdomen and kidneys

Treatment of kidney Stones

The treatment of kidney stones varies depending on their size, type, and the severity of symptoms. While some stones pass on their own, others may require medical intervention.

Treatment for Small Stones

Many smaller kidney stones, typically less than 5 millimeters in diameter, pass naturally through the urinary tract. To aid this process, doctors recommend:

• Increased fluid intake: Drinking 2 to 3 liters of water daily helps flush the stone out
• Pain management: Over-the-counter pain relievers such as acetaminophen (Tylenol) or ibuprofen (Advil) can help alleviate discomfort
• Alpha-blockers: Medications like tamsulosin (Flomax) relax the ureters, making it easier for the stone to pass

Treatment for Larger Stones

Larger stones, particularly those over 10 millimeters, may not pass on their own and require medical intervention. Treatment options include:

• Extracorporeal Shock Wave Lithotripsy (ESWL):This non-invasive procedure uses sound waves to break stones into smaller fragments that can pass naturally
• Ureteroscopy with Laser Lithotripsy:A small wire with a camera is inserted through the urethra to locate and break up the stone with a laser before removal
• Tunnel Surgery (Percutaneous Nephrolithotomy):A minimally invasive surgical procedure in which the stone is removed through a small incision in the back

Certain medications help manage kidney stones or prevent their recurrence:

• Allopurinol to reduce uric acid levels and prevent uric acid stones
• Thiazide diuretics to reduce calcium in the urine, preventing calcium stones
• Citrate supplements to reduce acidity in the urine, lowering the risk of stone formation
• Naproxen sodium (Aleve) for pain

Additional Procedures

If a kidney stone causes severe obstruction or infection, additional procedures may be required:

Shockwave Lithotripsy:Uses sound waves to break large stones into smaller pieces for easier passage

Tunnel Surgery (Percutaneous Nephrolithotomy):A surgeon removes stones through a small incision in the back, typically when the stone is too large or causing complications

Can kidney stones be prevented?

• Limiting foods high in sugar and sodium
• Limiting foods high in oxalates
• Drinking plenty of water
• Limiting animal proteins
• Maintaining a healthy weight

Foods that can cause kidney stones

In addition to drinking more water, dietary modification is crucial in preventing kidney stones. Here are some foods that you may need to avoid:

• Fish
• Shellfish
• Eggs
• Milk
• Cheese
• Beef
• Chicken
• Pork
• Organ meats
• Yogurt fast food
• Salty snacks
• Processed meats