Joan, a 60-year-old female, is supine on the floor, with her right hip supported by a pillow. "I broke my hip," she says calmly. "As long as I don't try to move it doesn't hurt." She tells you she tripped on an area rug in her kitchen and landed directly on her right hip. She reports pain and tenderness to palpation and has normal distal sensation and circulation. As we discuss options to minimize her pain during movement, I think about how pain signals are transmitted from the injury area to the brain and wonder how we can accurately assess Joan's pain.

Pain is the leading emergency medicine complaint, and its underlying causes are often of secondary concern to the patient.¹ Patients expect EMS to acknowledge their pain, assess it and treat it. The first step in improving assessment and treatment is to understand the pathophysiology and assessment of pain.²

WHAT IS PAIN?
The desire for pain relief often supercedes a patient's desire to identify and resolve the cause of pain. A position paper by the National Association of EMS Physicians says, "The NAEMSP believes that the relief of pain and suffering of patients must be a priority for every emergency medical services system."³

Understanding the underlying process or pathophysiology increases the likelihood an EMT will act on that knowledge. It is easy to say "give aspirin to any adult patient with chest pain"; however, understanding the cause of pain, like ischemic cardiac tissue; knowing how to assess the pain and differentiate it from among other potential causes, such as cardiac chest pain/pressure vs. respiratory tightness and shortness of breath; and understanding that aspirin inhibits platelet aggregation leads to faster and more effective treatment.

Pain is defined by the patient, not the caregiver. The International Association for the Study of Pain states that pain is "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage."⁴

Pain is a protective mechanism whenever body tissue is damaged. The pain stimulus triggers a cascade of emotional, physical and sensory reactions to communicate and lessen the pain.²

There is no predictable relationship between tissue damage and pain. Patients often report pain significantly higher or lower than what we might expect based on observable damage.⁵ Pain is a personal experience. Two patients with an identical injury or illness may have very different pain response and tolerance.