Kidney stones are the result of an accumulation of dissolved minerals on the inner lining of the kidneys.
They are usually comprised of calcium oxalate but may be composed of several other compounds deposits.
Kidney stones can grow to the size of a golf ball while maintaining a sharp, crystalline structure.
The stones may be small and pass unnoticed through the urinary tract, but they may also cause extreme pain as they leave the body.
Kidney stones that remain inside the body can lead to many complications, including blockage of the ureter (the tube connecting the kidney to the bladder), obstructing the path that urine uses to leave the body. They can cause intense pain.
Causes of kidney stones
Kidney stones can vary in size. Some have been known to grow as large as golf balls.
The leading cause of kidney stones is a lack of water in the body.
Stones are more commonly found in individuals who drink less than the recommended eight to ten glasses of water a day.
When there is not enough water to dilute the uric acid (a component of urine), the urine becomes more acidic.
An excessively acidic environment in urine is conducive to the formation of kidney stones.
Medical conditions such as Crohn's disease, urinary tract infections, renal tubular acidosis, hyperparathyroidism, medullary sponge kidney, and Dent's disease increase the risk of kidney stones.
Symptoms of kidney stones
A kidney stone usually remains symptomless until it moves into the ureter. When symptoms of kidney stones become apparent, they commonly include:
- Severe pain in the groin and/or side
- Blood in urine
- Vomiting and nausea
- White blood cells or pus in the urine
- Reduced amount of urine excreted
- Burning sensation during urination
- Persistent urge to urinate
- Fever and chills (if there is an infection)
Who gets kidney stones?
Kidney stones are more common among males than females. Most people who experience kidney stones do so between the ages of 30 and 50. A family history of kidney stones also increases one's chances of developing them.
Similarly, a previous kidney stone occurrence increases the risk that a person will develop subsequent stones in the future if preventative action is not taken.
Certain medications can increase the risk of developing kidney stones. Scientists found that topiramate (Topamax), a drug commonly prescribed to treat seizures and migraine headaches, can increase the likelihood of kidney stones developing.
Additional risk factors for kidney stones include diets that are high in protein and sodium but low in calcium, a sedentary lifestyle, obesity, high blood pressure, and conditions that affect how calcium is absorbed in the body such as gastric bypass surgery, inflammatory bowel disease, and chronic diarrhea.
Diagnosis of kidney stones
Several different tests can verify the existence of a kidney stone. A physical examination may reveal colicky pain (in the groin) and pain in the lower back by the kidneys - often warning signs of the condition.
An analysis of the urine will indicate whether or not there is blood in the urine and if there is a subsequent infection. Blood tests can be carried out to identify complications that may accompany a kidney stone and check the validity of the diagnosis.
A CT scan of the abdomen is one way to test for kidney stones. A CT scan will ascertain the state of the ureter, bladder, and kidneys, whether or not a stone exists, the kidney stone's exact size and location, whether or not a blockage exists, and the state of other organs in the area such as the appendix, aorta, and pancreas.
Pregnant women should receive an ultrasound rather than a CT scan to avoid unnecessary radiation.
Once a patient is diagnosed with a kidney stone, simple X-rays will be used to track the stone's progress through the excretory system.
Treatments for kidney stones
Lithotripsy involves sending a shockwave into the kidney stone to break it into smaller pieces.
Treating kidney stones is primarily focused on symptom management; passing a stone can be very painful. If a person has a history of kidney stones, home treatment may be suitable. Individuals who have never passed a kidney stone should speak with a doctor.
If hospital treatment is needed, the patient may be rehydrated via an intravenous tube and administered anti-inflammatory medication.
Narcotics are often used in an effort to make the pain of passing the stone tolerable. Antiemetic medication can be used in patients suffering from nausea and vomiting.
In some cases, a urologist can perform a shock wave therapy called lithotripsy - a treatment that will break the kidney stone into smaller pieces and allow it to pass.
Patients with large stones located in regions that do not allow for lithotripsy may receive surgical procedures such as percutaneous nephrolithotomy (removal of the stone via an incision in the back) or ureteroscopic stone removal (removal of the stone via a thin tube into the urethra).
Prevention of kidney stones
For individuals in good health, preventing kidney stones can be as easy as staying hydrated. Diluting the urine with water keeps the minerals from concentrating and forming stones. When one's urine is clear, rather than yellow in color, the chance of stone formation is reduced.
Doctors may also prescribe medicines to prevent certain types of stones for individuals who are at higher risk.