The normal human body temperature range is typically stated as 36.5–37.5 °C (97.7–99.5 °F). The average internal temperature is 37.0 °C (98.6 °F). It is typically maintained within this range by thermoregulation. Body temperature normally fluctuates over the day following circadian rhythms, with the lowest levels around 4 a.m. and the highest in the late afternoon.
Pathophysiology[edit | edit source]
The following are diseases and disorders in which issues in thermoregulation may occur. Each may present in people with ME or ME/CFS.
- Small fiber neuropathy, a type of neuropathy due to damage to the small myelinated and unmyelinated peripheral nerve fibers present in skin, peripheral nerves and organs
- Neurological diseases and disorders such as Parkinson's or multiple sclerosis
- Damage to the central nervous system or spinal cord, particularly those above T6 can cause dysregulation; “noxious stimuli” will trigger or worsen symptoms
- Hyperthyroidism, the overproduction of thyroid hormones, can cause heat intolerance
- Hypothyroidism, the underproduction or poor utilization of thyroid hormones, can cause cold intolerance
- Iron deficiency anemia, due to:
ME/CFS[edit | edit source]
Temperature dysregulation[edit | edit source]
- 53.9% - 58.7% of the 2073 patients in a Belgian study of 2001 reported symptom exacerbation in extremes of temperature.
- Katrina Berne reports a prevalence of 75-80% for heat/cold intolerance.
Temperature instability[edit | edit source]
Loss of thermostatic stability and intolerance of extremes of temperatures are separate diagnostic criteria in the International Consensus Criteria for ME. Indicators of temperature instability are listed as subnormal body temperature, marked fluctuations of temperature throughout the day; sweating episodes, recurrent feelings of feverishness with or without low grade fever, and cold extremities, e.g. fingers and toes.
References[edit | edit source]
- Osilla, Eva V.; Marsidi, Jennifer L.; Sharma, Sandeep (2022). "Physiology, Temperature Regulation". Treasure Island (FL): StatPearls Publishing. PMID 29939615. Cite journal requires
- Szelényi, Zoltán; Komoly, Sámuel (November 15, 2018). "Thermoregulation: From basic neuroscience to clinical neurology, part 2". Temperature: Multidisciplinary Biomedical Journal. 6 (1): 7–10. doi:10.1080/23328940.2018.1541680. ISSN 2332-8940. PMC 6422468.
- "Impaired Thermoregulation". PM&R KnowledgeNow. February 24, 2017. Retrieved May 27, 2022.
- Brigham, D.; Beard, J. (1996-12). "Iron and thermoregulation: a review". Critical Reviews in Food Science and Nutrition. 36 (8): 747–763. doi:10.1080/10408399609527748. ISSN 1040-8398. PMID 8989508. Check date values in:
- Rosenzweig, P. H.; Volpe, S. L. (1999-03). "Iron, thermoregulation, and metabolic rate". Critical Reviews in Food Science and Nutrition. 39 (2): 131–148. doi:10.1080/10408399908500491. ISSN 1040-8398. PMID 10198751. Check date values in:
- De Becker, P; McGregor, N; De Meirleir, K (September 2001), "A definition-based analysis of symptoms in a large cohort of patients with chronic fatigue syndrome.", Journal of Internal Medicine, 250 (3): 234-240, PMID 11555128
- Berne, Katrina (December 1, 1995). Running on Empty: The Complete Guide to Chronic Fatigue Syndrome (CFIDS) (2nd ed.). Hunter House. p. 58. ISBN 978-0897931915.
- London Criteria (2014)
- Carruthers, BM; van de Sande, MI; De Meirleir, KL; Klimas, NG; Broderick, G; Mitchell, T; Staines, D; Powles, ACP; Speight, N; Vallings, R; Bateman, L; Bell, DS; Carlo-Stella, N; Chia, J; Darragh, A; Gerken, A; Jo, D; Lewis, DP; Light, AR; Light, KC; Marshall-Gradisnik, S; McLaren-Howard, J; Mena, I; Miwa, K; Murovska, M; Stevens, SR (2012), Myalgic encephalomyelitis: Adult & Paediatric: International Consensus Primer for Medical Practitioners (PDF), ISBN 978-0-9739335-3-6
central nervous system (CNS) - One of the two parts of the human nervous system, the other part being the peripheral nervous system. The central nervous system consists of the brain and spinal cord, while the peripheral nervous system consists of nerves that travel from the central nervous system into the various organs and tissues of the body.
cofactor A substance that acts with another substance to bring about certain effects. In biochemistry, a cofactor is a molecule that is necessary for a given biochemical reaction, but is not an enzyme or substrate of the reaction.
enzyme a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.
neuroendocrine relating to hormones that influence the nervous system