These researchers often make these statements in journals, at professional conferences, and at public presentations. Each time they do, they ignore a line of evidence that points directly—and conclusively—to the main underlying cause of fibromyalgia. That cause is too little thyroid hormone regulation of patients’ bodies. The deficient thyroid hormone regulation results from two conditions. First is an undiagnosed or undertreated deficiency of thyroid hormone. Second is the resistance of patients’ tissues to thyroid hormone. "Resistance" means that patients’ tissues need higher than "normal" amounts of thyroid hormone to maintain normal metabolism.

Several factors in addition to deficient thyroid hormone regulation complicate many patients’ conditions. The four most common are nutritional deficiencies, an unwholesome diet, poor physical fitness, and drugs that slow metabolism. Some patients also have deficiencies or imbalances of other hormones, such as cortisol, estrogen, and progesterone.s

In this short article, I don’t attempt to explain that proof. My reason is that the explanation is extremely complicated. To enable readers to comprehend the proof, I had to use more words and categorical displays of evidence than space here allows. Showing that the proof is indisputable requires that we examine it within the context of a field of logical discourse—deductively formulated theory—familiar for the most part only to philosophers of science, deductivist logicians, and genuine scientists such as mathematical physicists. My editor, Jackie Yellin, and I worked hard to make the technical document as understandable as possible. We’ve done this so that physicians, medical researchers, and inquisitive patients can see that the premises of my argument are true, that the argument itself is valid, and that the overall proof is, indeed, incontestable.

Here, however, I simply present the line of evidence—evidence that most fibromyalgia researchers have entirely ignored. And because they’ve ignored the evidence, they’ve failed to understand the nature of and the solutions to fibromyalgia. I trust that most patients and doctors who open-mindedly look at the evidence will clearly see a tragic historical fact: other fibromyalgia researchers, through their studies over forty years, have unwittingly unearthed the holy grail of fibromyalgia; yet throughout those forty years, they’ve uniformly failed to realize what they found. They’ve failed to recognize what the evidence compels open-minded individuals to understand—that the problem of fibromyalgia is solved.

Line of Evidence. The evidence that too little thyroid hormone regulation is the main cause of fibromyalgia falls into four categories. These are: (1) symptoms, (2) studies of thyroid test results, (3) objectively verified abnormalities among patients, and (4) of most importance to patients, clinical trials with thyroid hormone therapy.

Table 1 lists the symptoms that fibromyalgia researchers call "associated symptoms" of fibromyalgia. These symptoms, of course, are classic symptoms of hypothyroidism and peripheral thyroid hormone resistance.

Low Resting Metabolic Rates of Fibromyalgia Patients (Table 2). In the first study, patients’ average resting metabolic rate was 29% below normal. The healthy women’s metabolic rates were only 8% below normal. (We consider a "reasonable reference range" for resting metabolic rates to be 10% below the predicted average.)

In the second study, the average resting metabolic rate for patients was 30% below normal. The average metabolic rate of healthy women was, again, 8% below normal.

Low Basal Body Temperature of Fibromyalgia Patients (Table 3). In the first study, patients’ average basal temperature was 96.95 F. The average for healthy women was 97.54 F. In the second study, the average temperature of patients was 96.38 F. The average for healthy controls was 97.54 F. Statistically, the patients’ temperatures in both studies were significantly lower than those of controls.

Why are these results so important? Because they show that the differences between patients and controls were highly statistically significant for both temperatures and resting metabolic rates. The bottom line is that compared to matched healthy controls, women with fibromyalgia had significantly lower resting metabolic rates and basal body temperatures—objective findings entirely consistent with too little thyroid hormone regulation.

Clinical Trials with Thyroid Hormone Therapy. Most fibromyalgia patients and their cooperative doctors want to know mainly one thing: Do we have an effective treatment? The answer is yes, although most fibromyalgia researchers have totally ignored the studies that show what the effective treatment is.

Summary. Is too little thyroid hormone regulation the main cause of fibromyalgia? The answer is a resounding yes! That the proof for this conclusion is irrefutable is clear only through one course of action—examining the evidence for the conclusion through the logic of science’s most advanced state of inquiry, deductively formulated theory. Nonetheless, the line of evidence I’ve given here should make the reasonable conclusion crystal clear: the medical problem of fibromyalgia is solved.

This conclusion, however, despite its granite-hard logical and scientific grounding, is—as are all scientific conclusions—a conjecture. And as a devout critical rationalist, I welcome any well-thought-out challenges to the conjecture.

(For references, please see the paper in Thyroid Science that I’ve based this article on.)

Table 4. Same objectively verified abnormalities in fibromyalgia (FM) as compared to hypothyroidism (HO) or peripheral resistance to thyroid hormone (PRTH). (Numbers under "FM" and "HO or PRTH" refer to publications referenced in the published paper, A, cited below.) ABNORMALITIES FM HO or PRTH Histological ^ Hyaluronic acid 34,35 36 ^ Ground substance proteoglycans 11,12,37-39 40-43 v Collagen  44,45 46,47 v Pyridinoline 48,49 50,51 v Procollagen III 52-54 36,55,56 v Hydroxyproline 44,45,48,49 47,50,57,58 ^ Mast cells 37,38,59 46,60-64 Cerebrospinal fluid ^ Substance P 65-68 69-72 v Dopamine (homovanillic acid) 73 74,75 v Tissue norepinephrine 73 76-78 v Urinary 5-hydroxyindole acetic acid 79 80 v Brain 5-hydroxytryptophan 73,81 82 ^ Nerve growth factor 83 84,85 Molecular ^ α-Adrenoceptors 86,87 88-95 Mitochondrial Ragged red fibers 96,97 98,99 v Cytochrome-c-oxidase 100 98,99 Physiological v Basal body temperature A,B (see below) 225,226,242,243 v Resting metabolic rate A,B (see below) 57,183,184 Exercise intolerance 101-104 105-108 v Muscle relaxation time 109 110 Blunted cortisol response to ACTH 111,112 113 Orthostatic hypotension 114,115 116 Joint hypermobility 117,118 119 v Brain blood flow 120-122 123 v Peripheral blood flow 124-126 127 Blunted sympathetic and end-organ response to stress 101,115,128-131 132-135 Excess urination 136,137 138,139 v Delta-wave and nonrestorative sleep 140,141 138,142-144 High-energy phosphates v Adenosine triphosphate (ATP) 145 146-149 ^ Phosphodiesters 150-152 153 ^ Inorganic phosphate (Pi) 151 153,154 v Phosphocreatine (PCr) 145 146 v PCr/Pi ratio 145 154,155 Carbohydrate metabolism ^ Pyruvate 156-158 105,156,159 v Lactic dehydrogenase (LDH) 150,156 150,156 v Intracellular pH 150 153,154 v Skeletal muscle glucose use 160 161-163 Endocrine v HPA axis function 131,164 165,166 v GH and IGF-1 167-169 170,171 ^ Hypothyroidism 20-26 N/A A. Lowe, J.C., Honeyman, G., and Yellin, J.: Lower resting metabolic rate and basal body temperature of fibromyalgia patients compared to matched healthy controls. Thyroid Science, 1:T1-T18, 2006. B. Lowe, J.C., Yellin, J., and Honeyman-Lowe, G.: Female fibromyalgia patients: lower resting metabolic rates than matched healthy controls. Medical Science Monitor, 12(8):CR1-CR8, 2006.