Pain:
The International Association for the Study of Pain describes pain as, “An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”. Pain is a subjective condition which includes personal experiences and emotions. Therefore, no one patient with pain can be treated with exactly the same methods or medications as another patient.

Acute Pain:
This usually has a sudden onset and a foreseeable end. It is most often associated with trauma or acute disease such as a broken limb or, for example, appendicitis.

Chronic Pain:
This is usually described as pain which has lasted for 3 or more months. However, it also applies to pain which has lasted longer than the expected normal healing time.

Pain terminologies and definitions that you may have read about or heard from your doctor are listed below.

Allodynia: Pain caused by a stimulus which does not normally provoke pain. eg. lightly touching uninjured skin causing pain.

Analgesia: Absence of pain in response to stimulation which would normally be painful. Eg. Not feeling a pin prick to the skin.

Dysaesthesia: An unpleasant abnormal sensation, whether spontaneous or evoked.

Hyperaesthesia: An increased sensitivity to stimulation. Eg A light touch is perceived as strong.

Hyperalgesia: An increased response to a stimulus which is normally painful. Eg. A pin prick is felt more painful than is normal.

Hyperpathia: A painful syndrome characterised by an abnormally painful reaction to a stimulus, especially a repetitive stimulus, as well as an increased threshold.

Hypoalgesia: Reduced feeling of pain to a normally painful stimulus.

Hypoaesthesia: Decreased sensitivity to stimulation, excluding the special senses.

Causalgia: A syndrome of sustained burning pain, allodynia and hyperpathia after traumatic nerve lesion, often combined with vasomotor dysfunction.

Central Pain: Pain initiated or caused by a primary lesion or dysfunction in the central nervous system. (Brain and spinal cord).

Neuralgia: Pain in the distribution of a nerve or nerves.

Neuritis: Inflammation of a nerve or nerves.

Neuropathic pain: Pain initiated or caused by a primary lesion or dysfunction in the nervous system.

Neuropathy: A disturbance of function or pathological change in a nerve. Mononeuropathy = in one nerve. Mononeuropathy Multiplex = in several nerves. Polyneuropathy = diffuse and bilateral.

Complex Regional Pain Syndrome I: CPRS I was formerly known as reflex sympathetic dystrophy, it consists of continuous pain (allodynia or hyperalgesia) in part of an extremity after a trauma. However, the pain does not correspond to the distribution of a single peripheral nerve. The pain is worse with movement and associated with sympathetic hyperactivity. The patient often complains of cool, clammy skin which later becomes pale, cold, stiff and atrophied. This process often occurs within weeks of a trauma, which may be mild.

Complex Regional Pain Syndrome II: CRPS 2 was formerly known as causalgia, it consists of burning pain in the distribution of a partially damaged peripheral nerve (most common the median, ulnar or sciatic). Pain may occur within a month of injury and may radiate beyond the nerve’s distribution. The condition results from abnormal sweat and vasomotor sympathetic efferent pathways, possibly due to abnormal connections between efferent sympathetic fibres and somatic sensory fibres at the site of the injury. The skin is classically cold, moist and swollen, later becoming atrophic.

Paraesthesia: An abnormal sensation which can be spontaneous or evoked. It usually feels like tingling or pins and needles and is not necessarily painful

Peripheral Neuropathic Pain: Pain initiated or caused by a primary lesion or dysfunction in the peripheral nervous system.

Nociceptor: A receptor preferentially sensitive to a noxious stimulus or to a stimulus which would become noxious if prolonged.

Nociceptice Pain: Pain which is transmitted by an undamaged nervous system.

Pain Threshold: The least experience of pain which a person can recognise.

Pain Tolerance Level: The greatest level of pain which a person is prepared to tolerate.