Glossary

A glossary of *key* ME-related terms.

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.

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
International Consensus Criteria

M
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

T
Two-day cardiopulmonary exercise test