Glossary of Pain






Acupuncture: a traditional Chinese therapeutic process in which specific points of the body are stimulated with needles to foster healing or pain relief.
Addiction: compulsive use of a drug for psychological purposes, such as moodalteration. This is distinct from scheduled use of a given dose of a drug for medical purposes, such as pain relief. (Also see pseudoaddiction.)
Analgesia: relief of pain.
Anesthesia: loss of sensation. Also a treatment that causes controlled analgesia, amnesia or recollection of events, and muscular relaxation.
Anesthesiologist: a physician who specializes in using medications that provide pain relief, relaxation, and lack of awareness during painful procedures. Anesthesiologists also monitor and maintain a patient’s vital functions during this time. They also manage pain for a few days following procedures. Some may also manage chronic painful conditions.
Annulus: The leathery covering of a disk surrounding the nucleus, or rubbery core.
Antidepressant: a medication used to treat depression. Some antidepressants may also be used to treat pain.
Arachnoid: the spiderweblike covering of the brain, spinal cord, cauda equina, and nerve roots.
Arachnoiditis: inflammation and scarring of the arachnoid, at times causing pain, numbness, and weakness in the legs and bowel, bladder, and sexual dysfunction. Arachnoiditis may be caused by spinal surgery, usually without serious consequences, or by old myelograms, with potentially serious results.
Autonomic nervous system: the part of the nervous system that functions in an automatic, unconscious fashion, regulating bodily functions such as heart rate, blood pressure, sweating, and digestion, for example.
Avulsion: forceful separation of connected parts, i.e., a root is ripped free of the spinal cord.
Axon: the part of a nerve cell that delivers impulses from that cell to other cells.


Block:  an injection of a chemical that blocks or stops the transmission of nerve impulses, resulting in possible pain relief, numbness, weakness, and other phenomena. These may be performed for diagnostic (to determine what is the cause of pain) or therapeutic (to alleviate pain) purposes.


CAT (computerized axial tomography) scan: see CT scan.
Cauda equina: Latin for horse’s tail. This is a group of nerve roots exiting the end of the spinal cord in the upper lumbar spine. These roots control the muscle power and sensation of the lower extremities  as well as bowel, bladder, and sexual function.
Cell body: the main part of a nerve cell.
Central nervous system: the brain and spinal cord, which receive and process sensory information from the rest of the body and respond by initiating muscle movement or some other response.
Cervical: pertaining to the neck.
Complex regional pain syndrome (CRPS): a type of chronic neuropathic pain, also previously known as reflex sympathetic dystrophy (RSD). It is characterized by burning pain; changes in skin color,  temperature, and texture; and deterioration of the vitality of the musculoskeletal system in the affected area.
Compression fracture: collapse of a bone (often a vertebral body) caused by trauma or by weakening from osteoporosis or cancer.
Corticosteroids: active hormones produced by the adrenal glands, producing biological effects on various bodily systems. Man-made analogues to these hormones possess potent anti-inflammatory and  pain-relieving properties and cause considerable side effects.
Cranial: pertaining to the head. Cranial nerves are those peripheral nerves which have their origins in the brain. Most of them function primarily on structures in the head.
CT (computerized tomography) scan: a diagnostic radiological technique combining a computer and X rays passed through the body at various angles. It provides detailed three-dimensional  information about the structure of the body.


Dependence:  the body’s adaptation to the presence of a drug, such as narcotics, alcohol, caffeine, and nicotine. When a person is dependent on a chemical, the lack of it causes withdrawal symptoms.
Dendrite:  part(s) of a nerve cell that receive incoming impulses from other nervecells.
Disk:  flattened circular structure something like a checker piece with a soft core. They lie between the vertebral bodies of the spine.
Discectomy:  a surgical procedure to remove disk material, usually following disk herniation.
Discogenic:  originating in the disk.
Discogram:  procedure to determine which disks cause pain. Radiological dye is injected into a disk and indicates the structural condition of the interior of the disk and its covering.
Dorsal:  pertaining to the back of the body, i.e., a dorsal root enters the back of the spinal cord.
Dorsal Root Entry Zone (DREZ):  the part of the spinal cord into which pain impulses from peripheral nerves enter the central nervous system. Damage to this zone can cause pain, as in postherpetic neuralgia, and neurosurgically induced lesions here can relieve it, as in a DREZ procedure.
Dura:  tough external covering of the brain, spinal cord, cauda equina, and nerve roots. Under the dura are the arachnoid, spinal fluid, and nervous system structures.
Dye:  pertaining to radiological dye, also known as contrast. This injected liquid is used to enhance the information gained from various radiological tests, including myelograms and some CAT scans. A special form of contrast is used to enhance MRI images.
Dysfunction: improper or abnormal function.


Electromyogram (EMG): an electrical diagnostic test. This is usually combined with a nerve conduction velocity (NCV) examination. Together they are used to evaluate disorders of the spinal nerve  roots, peripheral nerves, and muscles.
Endorphins: hormones or chemical substances manufactured by the body that relieve pain and produce euphoria. They are opioids, acting like drugs derived from opium (narcotics).
Epidural: pertaining to the area within the spinal canal outside the dura. It contains fat and veins.
Euphoria: a feeling of happiness and well-being.


Facet: a joint supporting the spine. Facets are located on either side of the spine and connect each vertebra to those above and below.
Fascia: a layer of connective tissue surrounding the muscles of the body.
Fibromyalgia: a diffuse, painful condition characterized by tender areas within muscles. It is not to be confused with myofascial pain, which is less diffuse and is associated with smaller focal areas of  muscle tenderness.
Flexion-extension X rays: X rays used to evaluate the degree of slippage of one vertebra over another. These X rays are taken from the side with the patient bending forward (flexes) and backward  (extends) in order to determine the stability of the spine during this kind of movement.
Foramen (plural: foramina): holes on either side of the spine through which the spinal roots exit the spinal canal.
Fusion: an operation in which one or more vertebrae of the spine are fused together with another piece of bone or metal hardware.


Ganglion (plural: ganglia): a mass of cell bodies of sensory or autonomic nerves. Each spinal root and certain cranial nerves have a ganglion. There are various autonomic ganglia near the spine and in  other parts of the body.
Gastrointestinal: pertaining to the digestive tract.


Herniate: the projection of tissue through a defect in surrounding tissue. In a disk herniation, the rubbery core of the disk pushes through the annulus. Sometimes, but not always, this material presses on a  nerve and causes pain.
Horse’s tail: see Cauda equina


Inflammation: reaction by the body involving local swelling, increased temperature, pain, and red coloration of the affected tissues. It is a response to damage, including infection.
Interventional: pertaining to invasive procedures, in which the body is penetrated with a needle or probe or opened surgically.
Intraspinal: inside the spinal canal. On this site, this term refers to drug delivery either into the epidural space or spinal fluid.
Intravenous: pertaining to delivery of a substance into a vein.
Invasive: pertaining to procedures involving penetration of or entry into the body.






Lamina: one of the two sides of the arch arising from the vertebral body. The arch makes up the back of the spinal canal.
Laminectomy: removal of one arch of a vertebra.
Laminotomy: removal of part of one arch of a vertebra.
Lesioning: partial or complete destruction of nerve tissue. On this Web site, lesions are made for the purpose of ending or moderating the pain messages sent by those nerves to the brain.
Ligamentum flavum: Latin for “yellow ligament.” These are the ligaments inside the spinal canal, which stabilize the spine. They bulge and become hard with calcium deposits with age, causing narrowing of the spinal canal and exerting pressure on the nerve roots.
Local anesthetic: a chemical that is placed in contact with nervous tissue and reduces the ability of nerves to transmit impulses, including those carrying pain messages.
Lumbar: having to do with the lower spine between the lowest rib and the pelvis


Medical: as pertains to therapy, nonsurgical treatment, usually involving medication.
Molecule: the basic unit of any chemical made up of more than one element.
Morphine: a narcotic analgesic or painkiller derived from the opium poppy.
Motor: pertaining to muscle contraction and movement.
MRI (magnetic resonance imaging): a diagnostic technique that provides threedimensional images of the structure of the body through exposure to a magnetic field, without the use of radiation.
Musculoskeletal: pertaining to ligaments, tendons, muscle, or bone. Musculoskeletal pain arises from these structures and in such disorders as arthritis, fibromyalgia, myofascial pain, most back and neck  pain, some headaches, temporomandibular-joint pain, and some cancer pain.
Myelogram: a diagnostic test in which radiological dye is injected into the spinal fluid; X rays and usually CAT scans are taken to evaluate sources of pressure on the spinal cord and nerve roots (such as  disk herniations, stenosis, spinal slippage).
Myofascial pain: pain related to focal areas of muscle contraction.


Narcotics: a class of drug that binds to specific receptors within the body that are also bound to by endorphins, our naturally occurring narcotic-like chemicals. Narcotics are used to relieve moderate to  severe pain.
Neuralgia: pain traveling along the course of a nerve or nerves that is caused by dysfunction or damage to the nerve(s) involved in the pain.
Neurologist: a physician specializing in the diagnosis and medical treatment of diseases and disorders of the nervous system. A  few sub-specialize in the drug-related treatment of pain.
Neuroma: a focal mass of scar tissue arising from a damaged nerve.
Neuron: a nerve cell. A neuron is composed of a cell body, dendrites, and an axon.
Neuropathic: pertaining to pain or unpleasant sensation caused by nervoussystem dysfunction or injury.
Neuropathy: disease of the peripheral nerves, often causing sensory loss, pain, or weakness. Neuropathy may involve one or more nerves.
Neurosurgeon: a physician specializing in the surgical treatment of nervoussystem diseases and disorders. A few subspecialize in the treatment of pain through interventional procedures.
Neurotransmitter: a chemical that carries messages between neurons or nerve cells.
NSAIDs (nonsteroidal anti-inflammatory drugs): a type of painkilling drugs that reduce inflammation. They block the production of prostaglandins,  chemicals that cause inflammation and initiate pain.  Aspirin is the most common. NSAID. Tylenol (acetaminophen) is not an NSAID.
Nucleus: the rubbery central portion of a disk.


Opiate: a drug derived from opium.
Opioid: a drug that acts like an opiate.
Orthopedist: a physician specializing in the surgical treatment of conditions of the bones, joints, muscles, tendons, and ligaments.


Pain: an unpleasant sensory or emotional experience, not necessarily associated with damage to the body.
PCA (patient-controlled analgesia): a method of pain relief in which patients are allowed to self-administer pain medication, usually by controlling the schedule by which they receive their medication. This  method usually involves a device attached to an intravenous infusion but may be used with subcutaneous or intraspinal drug delivery.
Peripheral nervous system: all the nerves carrying sensory and motor impulses to and from the central nervous system and the rest of the body.
Pharmacological: pertaining to drugs or chemicals with medically important biological effects.
Pharmacology: a scientific diskipline that deals with the design and function of chemicals that exert biological effects and that can be exploited medically.
Physiatrist: a physician specializing in rehabilitation and the use of physical medicine. Some physiatrists subspecialize in treating chronic pain.
Physical medicine: nonpharmacological, noninvasive, manual or mechanical methods to promote pain relief and increase function. These include physical therapy, braces, splints, externally applied heat  or cold, ultrasound, external electrical stimulation, and massage, for example.
Physical therapist: a specially trained and licensed medical professional who performs physical therapy. A physical therapist is not a physician and is supposed to provide physical-therapeutic treatment  only under prescription of a physician.
Postherpetic neuralgia: chronic pain at the site of an attack of shingles.
Prolapse: on this site, this pertains to bulging of the nucleus or center of a disk and an overlying area in the covering of the disk or annulus. This condition is less severe than a herniation.
Pseudoaddiction: drug-seeking (usually narcotic-seeking) behavior by a patient suffering from inadequately treated pain. The narcotics are sought for pain relief, not for psychological purposes, which  would represent true addiction.
Psychiatrist: a physician who specializes in the diagnosis and treatment of disorders of thought, emotion, and behavior. Treatment may include psychotherapy, medication, and rarely surgery on the  brain. Some psychiatrists have special expertise in working with chronic-pain patients.
Psychologist: a licensed mental-health professional who practices psychotherapy. Psychologists do not have a medical degree and cannot prescribe medication.
Psychotherapist: an individual who performs psychotherapy. Certain psychiatrists, clinical psychologists, certain social workers, and others may be considered psychotherapists.
Psychotherapy: nonpharmacological, nonsurgical, usually verbally based treatment for disorders of thought, emotion, or behavior.




Radicular pain: pain that radiates from a painful focus. Pain caused by root irritation or dysfunction also is referred to as radicular. (Radicle is the Latin origin of root.)
Radiofrequency: a type of energy which can be harnessed to produce heat. Using appropriate equipment, it can be used to achieve exquisitely localized, partial or complete destruction of tissue, including  nerves.
Radiological: pertaining to radiology, the medical specialty that obtains and interprets images of the internal structure of the body.
Radiologist: a physician who is trained in obtaining and interpreting images of the internal structure of the body with specialized diagnostic equipment, such as X rays, magnetic resonance imaging, and  sound waves (ultrasound).
Receptor: a three-dimensional structure composed of large molecules, often on the surface of a cell, to which other specific three-dimensional molecules (drugs, neurotransmitters, and hormones) can  bind in a “lock and key” interaction. This interaction may produce a biological effect, such as an increase or decrease in the impulses generated by a nerve cell containing the receptor.
Referred pain: pain transmitted to an area distant from its cause.
Reflex sympathetic dystrophy (RSD): See complex regional pain syndrome.
Rheumatologist: a physician who diagnoses and treats arthritis and other conditions involving the joints, muscles, or connective tissues.
Root: the portion of a nerve running between the spinal cord and foramen. Once the root exits the foramen, it is simply called a nerve. Roots are also referred to as spinal roots or nerve roots on this Web  site.


Side effect: an unwanted effect of a drug.
Spinal canal: the space within the spine through which course the spinal cord, roots, and their coverings. It is composed of the arch of the vertebra behind and the rear of the body in the front.
Spinal cord: the part of the central nervous system extending from the brain down to the upper lumbar spine. It serves to bring messages about the body (sensation) from the roots up to the brain and   ring messages from the brain down to the roots, from which these messages travel out to the peripheral nerves and affect the body.
Spinal fluid: a clear, colorless, waterlike fluid bathing the spinal cord and brain.
Spine: the column of bones, disks, and ligaments running from the base of the skull to the pelvis and enclosing the spinal cord, cauda equina, and nerve roots.
Stenosis: narrowing of a passage in the body. In this book, stenosis pertains to narrowing of the spinal canal or foramina due to arthritic overgrowth, disk bulges or herniation, bulging ligaments, or spinal  slippage.
Subcutaneous: under the skin.
Sympathetic: pertaining to a part of the autonomic nervous system. Historically, the sympathetic nerves have been implicated in the pain and dysfunction of what was called reflex sympathetic dystrophy  and is now called complex regional pain syndrome.


Temporomandibular: pertaining to the joints of the jaw, connecting the jaw (mandible) to the temporal bone of the skull. Temporomandibular-joint pain affects the local area of the joint and may radiate  out into the nearby face and head and down into the neck.
TENS (transcutaneous electrical nerve stimulation): a form of pain-relieving therapy in which mild electrical stimulation from a portable device is delivered to the skin through small electrodes glued to  the skin.
Test-negative pain: pain that has no cause that can be detected by plain X rays, CAT scans, MRIs, electrical tests, or laboratory-based diagnostic tools. This type of pain may be investigated with diagnostic  nerve blocks and discograms.
Tic douleureux: see trigeminal neuralgia.
Thoracic: pertaining to the chest area, or that part of the spine to which the ribs are attached.
Tolerance: the body’s adaptation to a drug so that the drug has fewer beneficial effects and side effects.
Trigger point: a small knotted bundle of fibers within a muscle that is the cause of myofascial muscle pain.
Trigeminal neuralgia: a form of neuropathic pain in which pain impulses arise from the trigeminal or fifth cranial nerve, its ganglion, or its connections in the central nervous system. Also known by the  French term tic douleureux (painful twitch), as the short-lived episodes of pain in this disorder are so severe as to cause patients to wince.




Vertebra (plural: vertebrae): a bone of the spine, composed of, in part, the vertebral body, lamina, and facets.
Vertebral bodies: the supporting part of a vertebra in the front of the spine, which takes the greatest weight. The disks are located between the vertebral bodies.
Vertebroplasty: a technique in which liquified orthopedic bone cement is injected into partially collapsed pain-generating bones (usually vertebral bodies) with the intent of relieving otherwise poorly  controlled pain. This therapy is especially beneficial in patients suffering from painful vertebral fractures caused by osteoporosis or cancer.
Visceral pain: pain arising from the internal organs or viscera.






Yellow ligament: see ligamentum flavum.


Visit us on... img img

Emile M. Hiesiger, M.D.

The Corinthian
345 East 37th Street
Suite 320
New York, NY 10016
• Phone (212) 697-1411 or
• Phone (212) 263-6123
• Fax (212) 697-1399

Add us to your contacts. Snap below!


*instructions for qrCode use