Kidney stones and bladder stones are hard deposits of minerals and salts that form in the urinary tract. Other names for stones in the urinary tract include renal calculi, urolithiasis, and nephrolithiasis. Bladder stones & kidney stones develop in concentrated urine. When urine is concentrated, it causes the minerals in the urine to crystallize and form stones. 

Please continue reading to learn some of the key differences between bladder stones & kidney stones.

A brief overview of the urinary tract

To better understand kidney and bladder stones, let’s first take a quick look at the urinary tract. It consists of a pair of kidneys, which are fist-size organs, one on each side of the spine in the lower abdomen. The kidneys maintain the body's fluid and chemical balance. They clean waste from the blood and remove it in the form of urine. The urine made by the kidneys empties into a thin, small tube called a ureter. There is a pair of ureters, one on each side, that collect urine from the two kidneys and carry it to the urinary bladder, where it is stored. Finally, the urine leaves the body through the urethra.

Is a bladder stone the same as a kidney stone?

The term kidney stone is a broad one. It is frequently used to refer to stones in all parts of the urinary system. However, specifically speaking, kidney stones form in the kidneys, and bladder stones form in the urinary bladder. Some stones can form in a kidney and travel through the ureter to the bladder. If a stone traveling from the kidney gets stuck in the ureter, it is called a ureteral stone.

What causes kidney and bladder stones?

As mentioned above, stones form in concentrated urine when minerals and salts crystallize and bind together. Possible causes for developing bladder stones and kidney stones include: 

• Dehydration (drinking too little water)
• Too much or too little exercise 
• Obesity
• Weight loss surgery
• Eating salty or sugary foods
• Eating too much fructose (found in fresh fruits)
• Urinary tract infection or inflammation
• Prostate gland enlargement in men, which obstructs the flow of urine
• Damaged nerves due to stroke, spinal cord injury, or other causes, which can cause neurogenic bladder (incomplete emptying of the bladder)
• Family history of kidney or bladder stones 
• Certain supplements and medications 
• Medical devices like catheters, stents, and contraceptive devices

What are the risk factors for developing bladder stones and kidney stones?

The main risk factors for bladder stones are obstructions that block the flow of urine. Another risk factor is damage to nerves that control bladder function. Men over the age of 50 are at particularly high risk of bladder stones.

Several factors can increase the risk of developing stones in the kidneys. Risk factors include dehydration (which leads to concentrated urine); a diet high in salt or sugar; a family history of kidney stones; obesity; gastric bypass surgery; medical conditions such as inflammatory bowel disease, repeated urinary tract infections, hyperparathyroidism (overactive parathyroid glands), cystinuria, acidic urine, and renal tubular acidosis; and taking certain medications and supplements like vitamin supplements, calcium-based antacids, laxative overuse, and some medications used to treat a medical condition like migraines or depression.

What does a bladder stone feel like?

Small bladder stones do not usually cause any symptoms. However, if a stone irritates the bladder wall or bladder lining or if there are larger stones, then there can be symptoms such as lower abdominal pain, frequent urination, pain with urination, interruption in urine flow, cloudy or dark-colored urine, blood in the urine. 

What does a kidney stone feel like?

Kidney stones do not cause symptoms unless they move around in the kidney or travel to the ureter (the tube that connects the kidney to the bladder). A stone stuck in the ureter can cause severe, sharp pain in the back or side that comes and goes and varies in intensity. The pain can radiate to the groin. There can also be frequent urination, a burning sensation with urination, pink or red or brown-colored urine, and foul-smelling urine. Other symptoms may include fever, chills, nausea, and vomiting.

How are kidney and bladder stones diagnosed?

Healthcare providers can diagnose stones based on your symptoms and physical exam. Other tests may include:

• In men, a rectal exam to check for an enlarged prostate gland.
• Urine tests to check for a urinary tract infection, blood in urine, and crystallized minerals.
• Blood tests to check uric acid levels and kidney function.
• Imaging studies like X-ray, CT scan, or ultrasound to detect the number and location of kidney and bladder stones.
• Analysis of passed stones caught in a strainer to check the type (calcium oxalate, struvite, uric acid, or cystine stones).

How are bladder and kidney stones treated?

Treatment for Bladder Stones

Your doctor may ask you to do nothing more than drink plenty of water for bladder stones. This can increase urination and may help small stones to pass without any specific treatment. Hydration can also prevent bladder stones, i.e., more stones or new stones from forming.

If aggressive hydration does not help the stones pass, your doctor may use a laser or ultrasound device to break the stones into smaller pieces and flush them out. This is a minimally invasive surgical procedure done using anesthesia. If the stones are too big to break up, surgical removal may be necessary. 

Treatment for Kidney Stones

Small kidney stones that cause minimal symptoms can be treated with hydration (drinking water) and pain relievers (ibuprofen, naproxen). Certain medications can help you pass kidney stones more easily, such as Flomax (tamsulosin) and Jalyn (tamsulosin and dutasteride). Large stones that do not pass on their own or cause symptoms may need to be treated with procedures such as:

• Extracorporeal shock wave lithotripsy (ESWL), a procedure in which strong vibrations or shock waves are used to break up kidney stones into smaller pieces that can be passed in urine. 
• Percutaneous nephrolithotomy, a surgical procedure to remove stones through an incision in the back.
• Ureteroscopy, a minimally invasive procedure to retrieve smaller stones in the ureter or kidney using a thin tube equipped with a small telescope and camera.
• Parathyroidectomy (removal of the parathyroid glands in the neck) if overactive parathyroid glands are causing high calcium levels and kidney stones as a result.

Are bladder stones life-threatening?

Most bladder stones and kidney stones are not life-threatening. However, if left untreated, stones in the urinary tract can lead to complications like chronic urinary difficulties (pain, frequent urination) and repeated UTIs (urinary tract infections). 

You should seek immediate medical attention if you develop the following signs and symptoms: 

• Severe pain
• Fever, chills, nausea, or vomiting
• Difficulty passing urine
• Blood in the urine

References:

1. https://www.mayoclinic.org/diseases-conditions/kidney-stones/symptoms-causes/syc-20355755
2. https://www.mayoclinic.org/diseases-conditions/bladder-stones/symptoms-causes/syc-20354339