<unk>  was originally defined as<unk>  that has lasted 6 months or longer. More recently it has been defined as<unk>  that persists longer than the temporal course of natural healing, associated with a particular type of injury or disease process.
The International Association for the Study of<unk>  defines<unk>  as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage." It is important to note that<unk>  is subjective in nature and is defined by the person experiencing it, and the medical community's understanding of<unk>  now includes the impact that the mind has in processing and interpreting<unk>  signals.
As a summary;<unk>  is defined as<unk>  that continues beyond the recognized time for the body to heal (usually 4-6 weeks)
Historically,<unk>  is underdiagnosed, and therefore undertreated<unk>  becomes a disease state itself without a physiologic role
Depending upon the distribution of symptoms, the<unk>  can be categorized as regional or diffuse
High rates of psychiatric co-morbidities exist with these conditions
Chronic pain
Delayed onset muscle soreness
Chronic wound
Work aversion
Dental fear
Erectile dysfunction risk factors
Osteoporosis risk factors
Headache risk factors