ABCESS: A localized collection of pus in any part of the body.

ACCURACY: The property of a measurement that determines how closely a measured value or result approximates the true value. Accuracy is reduced by systematic error (bias) for the observer, the instrument or the subject.

ACOUSTIC NEURINOMAS: Benign tumor of the hearing nerve (eighth nerve). A progressively enlarging, benign tumor, usually within the internal auditory canal or hearing nerve.

ACTION TREMOR: A type of tremor that occurs during voluntary movements, such as lifting a cup to one's mouth.

ACTIVATOR ADJUSTING INSTRUMENT: An instrument used by chiropractors who assert that slightly misaligned vertebrae can be tapped back into place with a spring-loaded mallet. "Activator Methods (AM) Chiropractic Technique" is a diagnostic and treatment system centered on the idea that leg-length analysis can determine when to adjust and when not to adjust the spine. Proponents claim that its procedures "generally enable the clinician to confidently and consistently identify subluxations. Most chiropractic colleges offer an elective course, and the leading proponents sponsor weekend seminars throughout the United States. The system is based on a concept of "functional short leg" -- which is an "apparent" difference in length, not an anatomical difference. To determine where the alleged subluxation is located, the practitioner holds the patient's feet in various prescribed ways while the patient lies facedown on an examining table. Other parts of the body may be tested in various other ways. If any inequality or "imbalance" is found, the practitioner taps various points along the spine, pelvis, and/or elsewhere with the Activator instrument until the legs appear to be equal in length. This approach is not a method of spinal manipulation (see Manipulation). Despite this, the FDA has approved the Activator Adjusting Instrument for "chiropractic adjustment of the spine and extremities." Activator Methods has serious flaws and employs dubious concepts. Despite this, many AM practitioners tell their patients that use of an Activator tool is a "state of the art" procedure that replaces the "old" method of manual spinal manipulation. The Activator tool and the AM system is viewed skeptically by many in mainstream chiropractic.

ACTIVE CARE: Modes of treatment/care requiring "active" involvement, participation, and responsibility on the part of the patient in recovery and rehabilitation.

ACUTE: New, for a short time, as opposed to chronic. For many health conditions, including back pain, acute implies that the condition is less than a few months old. After that, it becomes, chronic. The term "sub-acute" is often used to describe the transition period, when acute problems become less symptomatic, controlled, or treated to the point of plateau, but not to the point of being chronic. Subacute also is implied when a new, acute condition becomes suddenly without symptoms, but the underlying condition remains unresolved.

ACUTE CARE PROGRAM: Care directed primarily towards the relief of symptoms. It is designed to promote anatomical rest, diminish muscular spasm, reduce inflammation, and alleviate pain.

ADENOCARCINOMA: Cancer arising from secretory cells, often in a gland. Breast and pancreatic cancers are usually adenocarcinomas.

ADENOMA: A benign growth formed of glandular tissue.

ADJUNCTIVE THERAPY/MODALITIES: Procedures/equipment that are often used by chiropractors in conjunction with the delivery of an adjustment to facilitate or enhance the adjustment.

ADJUSTMENT: In chiropractic terms, a form of treatment where the application of force is to reduce spine or extremity joint dysfunctions or subluxations. There are many different types of adjustments and styles of adjustments. Mainstream chiropractic involves the use of a high velocity - low amplitude joint manipulation, done by hand.

ADVERTISING: A means of communicating with the public information pertaining to a chiropractor's practice.

AFFERENT (NEURON): Transmits impulses to the central nervous system. For example, our senses are afferent, like from the skin to the brain. The opposite is "efferent." An acutely malfunctioning joint, or a broken bone causes "afferent bombardment" to the spinal cord. The central nervous system responds with efferent nerve signals, e.g. telling muscles to spasm.

AGNOSIA: Absence of the ability to recognize the form and nature of persons and things.

AGRAPHIA: Loss of the power of writing, due either to muscular incoordination or to an inability to phrase thought.

AMAUROSIS: Loss of vision without discoverable lesion in the eye structures or optic nerve.

AMAUROSIS FUGAX: Temporary blindness occurring in short periods.

AMENORRHEA - Absence of the menses, due to causes other than pregnancy or advancing age. Female athletes who lose too much body fat also develop amenorrhea.

AMNESIA - Loss of memory caused by brain damage or by severe emotional trauma.

ANALGESIA - Loss of sense to pain, and/or loss of response to a painful stimulus.

ANALYSIS: The act of separating the clinical evaluation of a condition or disease into components as part of the process of forming a clinical impression or diagnosis.

ANECDOTAL EVIDENCE: A published account of an observation or experience. This includes categories and classifications of procedures, technologies, or equipment that have not been investigated using the experimental method.

ANESTHESIA - Loss of sensation of a body part or of the body, or the loss of consciousness when a drug has been administered.

ANESTHESIOLOGIST - Physician who administers painkilling or anesthesia medications during surgery or other medical procedures.

ANEURYSM - Dilation of an artery, formed by a circumscribed enlargement of its wall.

ANGIOGRAM - A study which shows the blood vessels leading to and in the brain by injecting a dye, or contrast substance, through a catheter placed in an artery in the leg.

ANGIOGRAPHY - Radiography of blood vessels using the injection of material opaque to x-rays to give better definition to the vessels.

ANGIOMA - A tumor whose cells tend to form blood vessels (hemangioma) or lymph vessels (lymphangioma).

ANNULUS FIBROSIS - The outer, fibrous, ring-like portion of an intervertebral disc.

ANOREXIA - A condition marked by loss of appetite leading to weight loss.

ANOSMIC - No sense of smell.

ANOXIA - Total lack of oxygen supply.

ANTERIOR - Front of the body or situated nearer the front of the body.

ANTEROLATERAL - Situated or occurring in front of and to the outer side of the body.

ANTEROMEDIAL - Situated or occurring in front of and towards the midline of the body.

ANTHROPOMETRY: The study of proportional relationships between the shape, weight and size of body segments.

ANTICOAGULANT - A medication that prevents coagulation of the blood.

ANTI-DIURETIC - An agent which reduces the output of urine. Anti-diuretic hormone (ADH) is formed in the hypothalamus and stored in the posterior pituitary gland.

APHASIA - Difficulty with or loss of use of language in any of several ways, including reading, writing, or speaking. Failure of understanding written, printed, or spoken word. Related to specific lesions in the brain.

APNEA - Cessation of respiration; inability to get one's breath.

ARACHNOID - Middle layer of membranes covering the brain and spinal cord.

ARACHNOIDITIS - Inflammation of the arachnoid membrane. Most commonly seen within the spinal cord, around the spinal cord, and cauda equina.

ARNOLD-CHIARI MALFORMATION - A condition in which there is displacement of the medulla and cerebellum into the opening in the basilar part of the occipital bone. It is one of the causes of hydrocephalus and is usually accompanied by spina bifida and menigomyelocele.

ARTERIOSCLEROSIS - Thickening and calcification of the arterial wall with loss of elasticity and contractility.

ARTERIOVENOUS MALFORMATION (AVM) - Collection of blood vessels with one or several abnormal communications between arteries and veins which may cause hemorrhage or seizures.

ARTHRALGIA - Joint pain.

ARTHRITIS - Inflammation of a joint, usually characterized by swelling, pain and restriction of motion. Arthritis is often used as a global term to describe any type of degenerative joint condition, even though there may not be evidence of inflammation. In this case Arthrosis is more appropriate.

ARTHRODESIS - The fusion of bones across a joint space, thereby limiting or eliminating movement. It may occur spontaneously or as a result of a surgical procedure, such as fusion of the spine.

ARTHROPATHY - Any disease or disorder involving a joint.

ARTHROPLASTY - The surgical remodeling of a diseased or damaged joint.

ARTHROSCOPY - The procedure of visualizing the inside of a joint by means of an arthroscope, an instrument inserted into a joint cavity to view the interior of a joint and correct certain abnormalities.

ARTICULAR - Pertaining to a joint?s connection, vis. where one bone connects or articulates with another.

ARTICULAR CARTILAGE ? The firm, pearly-white, glossy layer of cartilage that caps the articular surface of a bone. This tissue allows motion to take place with a minimum amount of friction. The degenerative loss of articular cartilage is the first stage of joint arthritis. The articular cartilage is a living colony of cells (chondrocytes) that produce the substance that cartilage consists of. Articular cartilage is "hylaline" cartilage, one of two types of cartilage, the other being "fibrous" cartilage.

ASSESSMENT: An examination performed with the intent of arriving at a qualitative or quantitative description of a patient's condition. The term includes any evaluation procedure performed for the purpose of obtaining information regarding the patient's state or condition. Disease (condition specific) assessments are outcome procedures that run the gamut from physiological tests to questionnaires. They are designed to elicit information about the specific signs and symptoms and other clinical characteristics of diseases or conditions. Condition specific assessments are usually more limited in scope than general health assessments. General health assessments are usually questionnaires completed by patients and scored for a number of attributes deemed important to the overall concept of health, i.e., decreased pain, improved mobility, improved psychological status.

ATAXIA - A loss of muscular coordination; abnormal clumsiness.

ATHETOSIS - A condition in which there is a succession of slow, writhing, involuntary movements of the fingers and hands, and sometimes of the toes and feet.

ATLAS - The first vertebra of the neck, articulating immediately with the skull, thus sustaining the globe of the head, whence the name.

ATONIC SEIZURE - Seizures that are characterized by a sudden loss of muscle tone, causing the individual to instantly drop to the floor, commonly known as "drop attacks."

ATROPHY - A wasting of the tissues of a body part.

AURA - Warning sign that people experience prior to the onset of a seizure or migraine, which may consist of a strange taste, bad feeling, visual disturbance or tingling sensation.

AUTONOMIC NERVOUS SYSTEM (ANS) ? "Involuntary" or "automatic" nervous system. The ANS is part of the peripheral nervous system (not the central nervous system, or brain/spinal cord), and has two branches, the sympathetic and parasympathetic. These two branches control many of our automatic bodily functions, like breathing, heart rate, and pupil dilation/constriction to light. This system of nerve cells whose activities are mostly considered beyond voluntary control, can be consciously affected. Yogi?s demonstrated this decades ago, consciously changing their skin temperature on their arms. ANS functions also can be consciously modulated using biofeedback devices.

AVASCULAR - Non-vascular; not provided with blood vessels, e.g., ligaments.

AXON - The part of a nerve cell that usually sends signals to other nerves or structures.