A kidney stone is a hard mass developed from crystals that separate from the urine within the urinary
tract. Normally, urine contains chemicals that prevent or inhibit the crystals from forming. These
inhibitors do not seem to work for everyone, however, so some people form stones. If the crystals remain
tiny enough, they will travel through the urinary tract and pass out of the body in the urine without being
Kidney stones may contain various combinations of chemicals. The most common type of stone contains calcium in
combination with either oxalate or phosphate. These chemicals are part of a person's normal diet and make up important
parts of the body, such as bones and muscles. A less common type of stone is caused by infection in the urinary tract.
This type of stone is called a struvite or infection stone. Another type of stone, uric acid stones, are a bit less
common, and cystine stones are rare.
Kidney stones often do not cause any symptoms. Usually, the first symptom of a kidney stone is extreme pain, which begins
suddenly when a stone moves in the urinary tract and blocks the flow of urine. Typically, a person feels a sharp, cramping
pain in the back and side in the area of the kidney or in the lower abdomen. Sometimes nausea and vomiting occur. Later,
pain may spread to the groin.
If the stone is too large to pass easily, pain continues as the muscles in the wall of the narrow ureter try to squeeze the
stone into the bladder. As the stone moves and the body tries to push it out, blood may appear in the urine, making the urine
pink. As the stone moves down the ureter, closer to the bladder, a person may feel the need to urinate more often or feel a
burning sensation during urination. If fever and chills accompany any of these symptoms, an infection may be present. In this
case, a person should contact a doctor immediately.
Return to Our Services