Pain

The IASP (International Association for the Study of Pain) defines pain as An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

Chronic Pain is defined as pain that persists for more than 3 months. Chronic pain can be either nociceptive or neuropathic. Nociceptive pain is linked with an external stimulus. Neuropathic pain is caused by nerve damage. Neuropathic pain occurs in the absence of detectable ongoing tissue damage.

Pain Terms

Allodynia
Pain due to a stimulus which does not normally provoke pain.

Analgesia
Absence of pain in response to stimulation which would normally be painful.

Anesthesia Dolorosa 
Pain in an area or region which is anesthetic.

Causalgia
A syndrome of sustained burning pain, allodynia, and hyperpathia after a traumatic nerve lesion, often combined with vasomotor and sudomotor dysfunction and later trophic changes.

Central Pain
Pain initiated or caused by a primary lesion or dysfunction in the central nervous system.

Dysesthesia
An unpleasant abnormal sensation, whether spontaneous or evoked.

Hyperalgesia
An increased response to a stimulus which is normally painful. Hyperesthesia Increased sensitivity to stimulation, excluding the special senses.

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

Hypoalgesia
Diminished pain in response to a normally painful stimulus.

Hypoesthesia
Decreased sensitivity to stimulation, excluding the special senses.

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: in one nerve, mononeuropathy; in several nerves, mononeuropathy multiplex; if diffuse and bilateral, polyneuropathy.

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

Noxious Stimulus 
A noxious stimulus is one which is damaging to normal tissues.

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

Paresthesia
An abnormal sensation, whether spontaneous or evoked.

Peripheral Neurogenic
Pain Pain initiated or caused by a primary lesion or dysfunction or transitory perturbation in the peripheral nervous system.

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

Common Pain Problems

Headaches can be caused by muscle tension, migraine, neck problems (cervical disc prolapses) and less commonly by strokes, brain tumors and head injury.

Face Pain: A condition called Trigeminal Neuralgia is caused by pressure on the Vth Cranial nerve next to the brainstem. This is often due to an abnormal position of a blood vessel compressing this nerve. Rarely tumors and arteriovenous malformations can cause this problem.

Neck Pain and Back Pain: This can be caused by slipped discs or herniated discs which press on nerve roots in the spine. Other causes include facet degeneration and bony spurs pressing on the nerve roots. Chemicals produced by degenerating discs can also be a cause of such pain. Instability in the spine can cause pain. This can be degenerative or subsequent to an injury.

Sciatica: This refers to pain shooting down a leg. This is often a sign of nerve root compression by a slipped disc.

Hand Pain: This can be caused by herniated discs in the neck or by thickened ligaments pressing peripheral nerves in the wrist – carpal tunnel syndrome (median nerve) or in the elbow-cubital tunnel syndrome (ulnar nerve).

Other pain syndromes: Reflex sympathetic dystrophy (RSD), fibromyalgia, amputation/phantom pain, post-herpetic neuralgia, brachial/lumbar plexus avulsion pain, T2 syndrome etc.