Pain is defined by the “International Association for the Study of Pain“ (IASP) as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. “Sensory experience” refers to the quality of pain, e.g. burning, piercing, tearing, and to its strength. “Emotional experience” refers to the emotional aspects of pain, e.g. agonizing, grueling or exhausting.
Acute pain can be very unpleasant, but usually subsides quickly after its cause disappears or is treated. It has a warning function that can be life-saving in extreme cases.
In chronic pain, this warning function no longer exists. On the contrary, the pain has become a problem of its own and must be regarded and treated as such.
According to the underlying mechanisms, three basic kinds of pain can be separated: receptor pain, neural pain and mixed forms.
Receptor pain, also called nociceptive pain, is the typical pain occurring after an injury. It is picked up by pain receptors (“nociceptors”) and conducted to the brain where the actual pain perception takes place.
Examples are acute injuries, postoperative pain, bone fractures, sports injuries, injuries of skin and mucous membranes, joint pain, back pain, tumor pain, intestinal pain, headache and inflammatory pain.
Neural pain – also referred to as neuropathic pain – on the other hand occurs through direct damage or malfunction of pain-conducting nerve fibers. Because of the structure of the nervous system, it is entirely possible that the pain is not felt at the site of the damage, but in another part of the body (e.g. damage in the back, but pain radiating into a leg). Examples are back pain with neural damage, phantom pain, post-zoster neuralgia (pain after shingles) and diabetic polyneuropathy.
Receptor pain and neural pain can come in mixed form. Examples are chronic back pain, tumor pain with nerve infiltration and pain in the context of osteoarthritis.
In order to diagnose pain as accurately as possible, several questions need to be answered, like where is the pain located, how does it feel, when did it start, how long does it endure, when does it occur and what factors have a positive or negative influence on it.
The strength of the pain is an important parameter in regard to pharmacological treatment. It can be measured with visual analogue scales, on which the patient can decide on the strength of their pain on a scale, e.g. between 0 and 10.
Originally developed for tumor pain, the WHO pain pyramid can also be used for chronic pain of other etiology. It distinguishes between weak, moderate and strong pain.
In the sign-in area, specialists can find a British guideline on the management of chronic pain in persons over 16 years old, at: