PAIN. Pain is an unpleasant sensory or emotional     experience, which is usually associated with or described in terms of tissue damage, or both. Pain acts as a warning signal that an injury is immediately impending, such as touching a hot object, or has occurred. The injury may be a broken limb with damage to the surrounding tissue.

ACUTE PAIN. Acute pain is a symptom with a recognizable cause. Sweating, crying, rising blood pressure and heart rate may be signs for a doctor that acute pain is being experienced. It continues as long as damage exists but goes away when the damage is repaired or is relieved. This may be for up to 4 months or so. If the pain does not go away then there is something else going on.

CHRONIC PAIN. Sufferers from chronic pain experience a continuing background pain, and have to cope with periodic increases in pain. This is pain that persists for longer than the normal course of a healing injury or of a disease. It may have begun with or without an injury, but it is no longer a warning sign. If there is no apparent damage to be repaired, then this chronic pain has no obvious value or biological function. It is useless for the body and seems to the sufferer to be a futile experience. The rising blood pressure and heart rate of acute pain will be absent. Its' continuance is an isolating situation and at its' worst may become the focus of entire existence. The desire to withdraw from one's normal life style, for the period of the worst pain, is not unusual. Coping with unexpected increases in pain levels is difficult.

Myths about chronic pain include the accusation of having a low pain threshold, of wanting drugs or being poor at coping.

NOCICEPTIVE PAIN. This is caused by tissue injury in the joints, bones, muscles and various internal organs. The patient's nervous system is functioning normally, picks up the injury and transmits the information to the brain.

NEUROPATHIC PAIN. This is different to 'normal' or somatic pain. It is any pain in which the mechanism arises in the sensory processes of the peripheral or central nervous system. This is the pain which can occur after nerve damage. Some clinical neuroscientists may restrict the definition to pain originating in the peripheral nerves and their roots. If there is any problem in the nervous system the transmission of the information to the brain will be flawed. Some of the words commonly used to describe neuropathic pain symptoms include burning, tingling, numb, squeezing and itching. There may be electric shooting sensations. Neuropathic pain may be very resistant to treatment.

PAIN THRESHOLD. The least experience of pain that a person may perceive as pain.

PAIN TOLERANCE LEVEL. The greatest level of pain that a person is prepared to tolerate. This is the subjective experience of any individual.