Hypothyroidism is a pathologic condition caused by a deficiency of thyroid hormones. The thyroid secretes two hormones, T4 and T3. Only T3 is active. They are regulated by the TSH, a hormone secreted by the pituitary gland located at the base of the brain. Hypothyroidism is called primary when it is due to a disorder in the thyroid gland itself, in most cases an autoimmune disease (Hashimoto`s thyroiditis). It is called secondary or central, in 5 to 10% of cases, when it is due to a pituitary disorder. A rate of TSH elevated beyond the standard usually indicates hypothyroidism, but this is not always the rule. Be aware, and it is not known to all physicians, that a “normal“ TSH value does not exclude hypothyroidism. TSH often does not reflect a state of thyroid hypo-metabolism nevertheless already clinically manifest. Moreover, paradoxically, the rate of TSH is low or normal in secondary or central hypothyroidism, making in such case the diagnosis of hypothyroidism challenging and often ignored.
Why the study of hypothyroidism has its place in a site that deals with fibromyalgia?
Firstly, because these two diseases have very similar symptoms.
Secondly, because hypothyroidism is a major cause of fibromyalgia.
Thirdly, because in the clinical picture of hypothyroidism may also exist musculoskeletal pain, and number of patients labeled suffering from fibromyalgia in fact suffer from an undiagnosed hypothyroidism.
Fourth, because both disorders, fibromyalgia and Hashimoto`s hypothyroidism, may co-exist, both being of autoimmune origin (disorder of the immune system).
Fifthly, because if it is true that a physical or mental trauma can be the “trigger“ (trigger event) to the development of symptoms of fibromyalgia, it turns out that many of these patients already had a hypo-metabolic state of hypothyroidism before the trauma occurred.
Sixth, if in the general population secondary or central hypothyroidism is found only in 5 to 10% of the cases of hypothyroidism, hypothyroidism responsible of fibromyalgia is for over 50% of the cases a secondary or central hypothyroidism, diagnosis, as we have said above, usually misunderstood or ignored because of a low or normal TSH.
Seventh, therapeutically, because a large majority of fibromyalgia patients and chronic fatigue syndrome patients presenting symptoms of hypothyroidism with normal blood tests significantly improves with hormonal treatments that aim to restore thyroid metabolism.
Eighth, because ignorance of adrenal fatigue often associated with hypothyroidism, and also very common in patients with fibromyalgia and chronic fatigue syndrome, is sometimes responsible for the failure of thyroid hormonal replacement therapy and therefore for the failure of the treatment of fibromyalgia and chronic fatigue syndrome.
That`s why fibromyalgia and hypothyroidism are closely intricate, on both diagnostic and therapeutic plans.