There are two types of pain; fast and slow. The former triggers a fast-pain message; the latter produces a slow, aching sensation. Generally, fast pain corresponding to acute pain and the slow pain corresponds to chronic pain. Discussion of acute and chronica pain will be dicuss later. Fast pains generally serve as warning signal of sudden localized injury (Catalano, 1987, Wells & Nown, 1998). Hence, the purpose of fast pain is to attract our attention; to give a sharp warning that we have been damaged in some way that require a response to avoid further damage. Fast pain is transmitted along the cable network of nerve bundles by large-diameter A-beta nerve fibers. Hence, this is the type of pain that feels like pressure and touch (Catalano, 1987).
Slow pain on the other hand, involves a more complex emotional process. Slow pain is linked to pain tolerance, which changes according to our past experience and our present state of mind (Wells & Nown, 1998). Hence, ones mental attitude can influence how much slow pain one feels. In addition, slow pain are carried in smaller diameter A-delta and C nerve fibers (Catalano, 1987). A-delta pain are the sharp and stabbing pain that is felt from burn or cut; C fiber pain is typically referred to as "slow pain" or secondary pain (Catalano, 1987). Slow pain is the types of pain that produces dull aching sensation (Catalano, 1987).
Both fast and slow pain messages are transmitted to the brain by pain receptors, which are a network of nerve endings throughout the body. Fast-pain receptors are found beneath the surface of the skin. Slow-pain receptors are also located beneath the skin, but it also carries messages from the joints and large internal organs of the body. Discrimination between different pain stimuli (e.g. the prick of a needle and a burn from a hot stove) are possible because different types of pain receptors transmit different pain sensations to the brain (Wells & Nown, 1998). Thus, we are also, able to distinguish between fast and slow pain.
Furthermore, physical pain can be categorized as acute or chronic. Pain is general, and chronic pain is a multidimensional experience. Thus, Melzack and Casey proposed the following three distinct dimensions to the pain experience (Nicolas & Walsh, 1991).
Sensory-Discrimination Dimension. Electrochemical reception of noxious stimulation, afferent transmission, and initial central processing. This dimension is composed of experiencing the location, quality, and intensity of the painful sensations; it is mapped in time (e.g., constant vs. intermittent, acute vs. chronic) and space (location). This dimension includes the when, how long and where of pain. Cognitive-Evaluation Dimension -A dimension of ongoing perception and appraisal of the meaning of what is happening, or what might take place in relation to the sensation. This dimension is mapped in time (past, present, and future) and occurs at the level of the whole person within the social network. Affective-Motivational Dimension - A dimension of moods and a sense of meaning and relationship tot he desire to avoid harm or an expectation of harm; this dimension is also mapped in time and occurs at the level of the whole person within the social network.
In the acute pain state, the sensory-discriminative dimension dominates the pain experience and the cognitive-evaluation and affective-motivational dimension are less significant. Acute pain is define as having a "recent, discrete onset and usually subsided in less than one month" (Bono & Zaza, 1988, Nicolas & Walsh, 1991). Over time, the localization sensory-discriminative dimension of pain becomes vaguer and "makes less sense" (Nicolas & Walsh, 1991). During this time, the cognitive and affective dimensions become more prominent and over time, a type of behavior termed chronic pain syndrome is recognized; this is usually characterized by feeling of depression, anxiety, and increased pain.
Chronic pain is defined as pain that has persisted for six months or longer (Gershon, 1986, Bono & Zaza, 1988). In the chronic pain state, the cognitive-evaluation and affective-motivational dimensions dominates the experience. Since most physicians are used to treating acute injuries that improved within the appropriate time period, when it comes to treating chronic pain there is a lacking in knowledge (Nicolas & Walsh, 1991).
Back to Title Page