Glossary

A glossary of *key* ME-related terms.

B
B cell -- B lymphocyte, or a type of white blood cell, is involved in the immune response by secreting antibodies to ward off infections. In mammals, they are mostly matured in the bone marrow.

Biopsychosocial model (BPS model) -- a school of thought, usually based in psychology, which claims illness and disease to be the result of the intermingling of biological, psychological and social causes.

C
Canadian Consensus Criteria (CCC) -- a criteria used to diagnose ME/CFS (sic), developed by a group of clinicians in 2003. Often considered the most complex criteria, with the lowest number of patients meeting the criteria. Led to the development of the International Consensus Criteria in 2011.

Chronic Fatigue Syndrome (CFS) -- may be more likely to refer to those diagnosed using the Fukuda Criteria or the Oxford definition. Commonly used in the United States as the name of the disease. Viewed by some patients as dismissive and derogatory.

Cognitive behavioral therapy (CBT) --  A type of psychotherapy geared toward modifying unhealthy thinking, behaviors or illness beliefs. One of the treatment arms used in the controversial PACE Trial.

Crash -- see 'post-exertional malaise'

E
Energy Envelope Theory

G
Graded Exercise Therapy (GET) - exercise therapy which gradually increases the patient's activity levels. Considered controversial in the treatment or management of ME.

H
Heart rate monitor (HRM) - (noun) a device that measures your heart rate / pulse. Typically a chest strap, wrist strap, or mobile phone app. See also Pacing with a heart rate monitor

Heart rate variability (HRV) - a measurement of the specific changes in time (or variability) between successive heart beats. This is related to autonomic and cardiovascular function. See also Pacing with a heart rate monitor

I
ICD -- International Classification of Diseases. A system of medical codes created by the World Health Organization (WHO) for diseases and other health related conditions for the purpose of international consistency. The 11th revision, or ICD-11, is due in 2018.

International Consensus Criteria

M
Medically unexplained physical symptoms (MUPS) -- symptoms for which a medical cause is not found.

Medically unexplained symptoms (MUS) -- see Medically unexplained physical symptoms.

metabolite -- a substance produced by, or involved in metabolism.

metabolomics -- the study and analysis of the chemical processes of metabolites within cells, tissues or organisms.

microbiome -- the collective of microscopic organisms (including bacteria, viruses and fungi) and their genetic material, which are present in a particular environment, particularly in the human body.

mitochondria -- organelles or subunits within a cell. Their primary role is to take in nutrients and produce energy for the cell in the form of ATP (adenosine triphosphate). This process requires oxygen and is called aerobic respiration.

Myalgic Encephalomyelitis

O
Orthostatic intolerance (OI) -- the development of symptoms when standing upright which are relieved when reclining; may be due to dysautonomia

P
pacing - the practice of staying within one's 'energy envelope' by interspersing periods of activity with periods of rest. Patients may use pacing with a heart rate monitor as an objective measure of exertion.

payback - see post-exertional malaise

post-exertional malaise (PEM)- (noun) a worsening of ME symptoms due to physical or cognitive exertion

post-exertional neuroimmune exhaustion -- see post-exertional malaise

Postural orthostatic tachycardia syndrome (POTS) -- a form of orthostatic intolerance where the cardinal symptom is excessive tachycardia due to changing position (e.g. from lying down to sitting up).

PwME Person with Myalgic Encephalomyelitis

S
SF-36 Short Form (36) Health Survey -- a 36 item patient reported questionnaire, used to determine patient health status and quality of life

somatic -- relating to the physical body. In biology, all the cells of the body, except those which form egg or sperm.

T
T cell -- T lymphocyte, or a type of white blood cell, which is mostly produced or matured in the thymus gland (hence T-cell) and is involved in immune response on a cellular level. See also Dr. Mark Davis Research Update video.

Two-day cardiopulmonary exercise test