Kidney stones are most prevalent in people age 20 to 50, are more common in men, and are most prevalent in Caucasians. Most stones are formed and excreted singly. Kidney stones come in virtually any color,though most are yellow to brown. They also come in a variety of shapes and sizes. The composition of the stone may tell something about how it is formed.
Significant pain is usually the first symptom of a kidney stone.
When a stone moves from the kidney into the ureter, pain can develop suddenly. If the stone is too large to pass easily, the severe, constant pain continues as the muscles in the walls of the ureter try to squeeze the stone along into the bladder. Sometimes there is blood in the urine, or a burning sensation occurs during urination. Occasionally, an increased frequency of urination can also indicate the presence of kidney stones. Kidney stones are typically diagnosed by x-ray, CT scan or ultrasound examination.