Final answer:
A kidney stone is a solid crystal that forms in a kidney from minerals in the urine. It can cause severe pain and may require surgical intervention or fragmentation to remove it. Common symptoms include colicky pain, hematuria, and obstruction of urine flow.
Step-by-step explanation:
A kidney stone, also known as a renal calculus, is a solid crystal that forms in a kidney from minerals in urine. Kidney stones can vary in size from as small as grains of sand to as large as a golf ball. They can cause severe pain when they pass through the urinary tract, and if they block a ureter, they may need to be removed surgically or fragmented using high-intensity ultrasound. Common symptoms of kidney stones include colicky pain, hematuria, and obstruction of urine flow.