As for what is fear biologically speaking, when a person experiences fear, certain areas in their brain such as the amygdala and the hypothalamus are immediately activated and appear to control the first physical response to fear.
Kidney Stones Overview. Kidney stones are small pebbles of salt and mineral in the urine. The most common symptom is severe pain. Most stones pass on their own, but medical procedures are used to remove some kidney stones.
kidney stone a calculus in the kidney, composed of crystals precipitated from the urine on a matrix of organic matter. Called also nephrolith and renal calculus.