When substances in the urine—such as calcium, oxalate, and phosphorus—become highly concentrated, kidney stones can form. People who do not drink enough fluids may also be at higher risk, as their urine is more concentrated.
A recent UCLA study “Prevalence of kidney stones in the United States” published in European Urology (PDF) reported on the risk factors that make a person especially likely to develop a kidney stone. Men are affected more often than women, and overweight and obese people are more likely to get a kidney stone than people of normal weight. In the United States, 8.8% of the population has had a kidney stone.
Kidney Stone Symptoms
People with kidney stones may see blood in the urine, experience an intense cramp in the back, or experience spasms in their lower abdomen. Many people who have small stones will have them pass through the body on their own, while large stones tend to get stuck in the urinary tract. Pain is often unrelated to stone size. Often the smallest stones can cause the most colic, while large stones may sit quietly in the kidney causing only a dull ache.
Kidney Stone Diagnosis
Diagnosing a kidney stone requires a physical exam and a medical history to be taken by a physician. Typically a urinalysis (testing of a urine sample), an abdominal x-ray, a computerized tomography (CT) scan, or an ultrasound will be done to complete the diagnosis.