Etymology and Classification of Pain
- Pain first attested in English in 1297, derived from Old French 'peine' and Latin 'poena'
- Pain also means torment, hardship, suffering in Late Latin and Greek
- Recommended features to describe a patient's pain: region, system, duration, intensity, cause
- Helps identify specific characteristics, determine treatment options, and improve communication
- Enables accurate diagnosis and management of pain conditions

Chronic versus Acute Pain
- Pain is usually transitory but can persist for years in some conditions
- Chronic pain lasts a long time, while acute pain resolves quickly
- Distinction based on duration, with varying definitions

Types of Pain
- Allodynia: pain in response to a normally painless stimulus
- Phantom pain: felt in amputated or disconnected body parts
- Causes of pain: abnormalities in the nervous system, nerve damage, spinal cord injury, diabetes, leprosy
- Functional effects of pain: impairments in attention, memory, problem-solving, information processing
- Negative emotions associated with pain: increased depression, anxiety, fear, anger

Theories and Understanding of Pain
- Historical theories proposed by ancient Greeks, Avicenna, Descartes
- Modern understanding: differentiation between noxious and non-noxious stimuli, nociceptors, pain signaling pathways

Evolutionary and Behavioral Role of Pain
- Pain is part of the body's defense system and serves as a warning signal
- Congenital insensitivity to pain reduces life expectancy
- Pain may be shaped by natural selection as a signal for relief and care
- Idiopathic pain may be an exception to pain's helpfulness for survival
- Pain thresholds: pain perception, pain threshold intensity, pain tolerance
- Assessment of pain: self-report, healthcare professionals' perception, pain intensity scales, multidimensional pain inventory
- Assessing pain in non-verbal individuals: observation of behaviors, changes in routine, crying in infants

Pain (Wikipedia)

This article is about physical pain. For mental or emotional pain, see Psychological pain. For other uses, see Pain (disambiguation).

Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage."

Pain
An illustration of wrist pain
Specialty	Neurology Pain medicine
Symptoms	Unpleasant sensory and emotional sensations
Duration	Typically depends on the cause
Types	Physical, psychological, psychogenic
Medication	Analgesic

Pain motivates organisms to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future. Most pain resolves once the noxious stimulus is removed and the body has healed, but it may persist despite removal of the stimulus and apparent healing of the body. Sometimes pain arises in the absence of any detectable stimulus, damage or disease.

Pain is the most common reason for physician consultation in most developed countries. It is a major symptom in many medical conditions, and can interfere with a person's quality of life and general functioning. People in pain experience impaired concentration, working memory, mental flexibility, problem solving and information processing speed, and are more likely to experience irritability, depression and anxiety.

Simple pain medications are useful in 20% to 70% of cases. Psychological factors such as social support, cognitive behavioral therapy, excitement, or distraction can affect pain's intensity or unpleasantness.