ME/CFS Society of WA: Glossary

Anorexia - Lack of appetite.

Ataxia - Incoordination and unsteadiness.

Case definition - a list of agreed symptoms that accurately describe or identify an illness or condition. Used in diagnosis in the absence of bio- or laboratory markers.

Chronic fatigue - Fatigue lasting 3 months or more. A 'symptom' of multiple illnesses and not to be confused with the disease 'Chronic Fatigue Syndrome' (Myalgic Encephalomyelitis).

Cognitive - Pertaining to cognition, the process of thinking, processing information, being aware, learning or judging.

Cognitive Behavioral Therapy (CBT) - A psychotherapy based on modifying cognitions, assumptions, beliefs and behaviors, with the aim of influencing disturbed emotions.

Diurnal - Recurring every day.

Dyspnea - Difficult or labored breathing, shortness of breath.

Fasciculations - Involuntary contractions or twitchings of groups of muscle fibers.

Fibromyalgia (FM) - A syndrome characterized by chronic pain, stiffness, and tenderness of muscles, tendons, and joints without detectable inflammation.

Lymph nodes - Small rounded or bean-shaped masses of lymphatic tissue surrounded by a capsule of connective tissue.

Multiple Chemical Sensitivity (MCS) - A chronic condition characterized by adverse and variable effects from exposure to low levels of chemicals or other substances in modern human environments.

Neurally Mediated Hypotension (NMH) – A condition in which there is an abnormal reflex interaction between the heart and the brain, both of which usually are structurally normal, causing low blood pressure. It can occur after being upright, exercise, or exposure to a warm environment.

Orthostatic Intolerance - The development of symptoms during upright standing, relieved by recumbency, lying down or sitting.

Pallor – Pale skin tone.

Postural Hypotension - A drop in blood pressure (hypotension) due to a change in body position (posture) when a person moves to a more vertical position.

Postural Orthostatic Tachycardia Syndrome (POTS) - A condition in which a change from the supine position to an upright position causes an abnormally large increase in heart rate, often, but not always accompanied by a fall in blood pressure.

Prevalence - The total number of cases of the disease in the population at a given time.

Triggering Event – An event (e.g. infection/toxic exposure/stress) which triggers the onset of an illness. Discreet and identifiable moment of onset.