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.
A kidney stone begins as a tiny piece of crystal in the kidney. When the urine leaves the kidney, it may carry the crystal out, or the crystal may stay in the kidney. If the crystal stays in the kidney, over time more small crystals join it and form a larger kidney stone.