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.
Definition & Facts. 1  A kidney stone is a solid, pebble-like piece of material that can form in one or both of your kidneys when high levels of certain minerals are in your urine. 2  You may have a kidney stone if you feel a sharp pain in your back, side, lower abdomen, or groin; or have blood in your urine. If you have a small stone that easily passes through your urinary tract, you may not have symptoms at all.