What Are Kidney Stones?
By Joseph Bennington-CastroMedically Reviewed by Robert Jasmer, MD
There are several different types of kidney stones, but each of them can cause a lot of pain.
Kidney stones are small chunks of solid material that can form in your kidneys, a pair of organs that filter your blood.
The "stones," which are usually yellow and brown, vary in size and shape.
https://www.everydayhealth.com/kidney-stones/guide/