Somatic Sensations: II. Pain, Headache, and Thermal Sensations Many, if not most, ailments of the body cause pain.Furthermore, the ability to diagnose different
diseasesdepends to a great extenton a physician‘s knowledgeof the different qualities ofpain. For these
reasons, the first part of this chapter is devoted mainly to pain and to the physiologic bases ofsome
associated clinical phenomena.
Pain Is a Protective Mechanis . Pain occurs whenever tissues are being damaged, and it
causes the individualto react to remove the pain stimulus. Even such simpleactivities as sitting for a
long time on the ischia can cause tissue destruction because of lack of blood flow to the skinwhere it is
compressed by the weight of the body.
