Strength training, aerobic exercise and stretching can prevent muscles from withering, reduce disability and even reduce pain intensity by 10% to 50%, Rainville says.

FORBES: On The Cover/Top Stories

The second shock in succession to the same location of the body produced higher pain intensity ratings than the first shock and (sic) that the third shock in succession to the same location of the body produced higher pain intensity ratings than the second shock in succession.

FORBES: Autism Shock Therapy Practiced In US Is Torture, Says UN Official

In a provocative new study, scientists reported Wednesday that they were able to "see" pain on brain scans and, for the first time, measure its intensity and tell whether a drug was relieving it.

WSJ: Doctors use brain scans to 'see' and measure pain

However, some people with acute pericarditis describe their chest pain as dull, achy or pressure-like instead, and of varying intensity.

CNN: Pericarditis