Metabolism requires a complex interaction of many organs and glands to convert food and nutrients into energy. The thyroid gland sends hormonal signals to other glands and organs throughout the body to control this busy process. The thyroid, in turn, receives signals from other glands to control its function.
Most importantly, the pituitary gland sends thyroid-stimulating hormone---TSH---to tell the thyroid to increase its function. An elevated TSH level means the thyroid isn't responding, so the pituitary keeps sending more TSH to try to stimulate the thyroid. Therefore, high TSH indicates low thyroid function, a situation called hypothyroidism, explains "Harrison's Textbook of Internal Medicine."
Goiter
As the pituitary continues to bombard the thyroid with TSH, the cells of the thyroid try to keep up with making thyroid hormone in response. All this hard work by the thyroid causes it to swell. This appears as a lump, called a goiter, at the base of the neck, explains the American Thyroid Association at thyroid.org. Sometimes barely noticeable, it can cause difficulty speaking or swallowing in extreme cases.
Fatigue
According to the September 2007 issue of "Endocrinology and Metabolism Clinics", when the thyroid doesn't function well, body systems and metabolism slow down. The overall effect includes feelings of fatigue and weakness that occur because the body is unable to generate the energy required to operate efficiently. With fatigue, patients also notice that they are more forgetful and may even begin to show signs of depression. If hypothyroidism continues for a long time, the function of the heart suffers and intolerance to exercise with extreme fatigue ensues.
Constipation
When the gastrointestinal system slows down in the hypothyroid condition, patients experience constipation as the most commonly reported GI symptom. Nausea joins the list of symptoms if emptying of the stomach slows as well. In spite of gastrointestinal discomfort and decreased appetite, weight gain still often occurs due to the altered metabolism, states the "Endocrinology and Metabolism Clinics" review.
Dry Skin
The "Postgraduate Medical Journal" explains that skin signs and symptoms may be the most sensitive indicators of hypothyroidism. Dry skin frequently signals a problem, especially if the skin also is cool and pale and has decreased ability to sweat. A history of being intolerant to cold along with hair loss from the body or head also increases the likelihood that a hypothyroid state exists. Puffiness of the skin with swelling around the eyes and on the front of the lower legs present later than dry skin alone. While the skin and other findings may be fairly good indicators, none of these symptoms of elevated TSH and hypothyroidism show enough specificity to make the diagnosis. A blood test showing the high TSH confirms the suspicion.
References
- American Thyroid Association: Patient Brochures, Hypothyroidism
- "Harrison's Textbook of Internal Medicine, 17th edition"; Anthony Fauci, Eugene Braunwald, et al, editors; 2009
- "Endocrinology and Metabolism Clinics"; Hypothyroidism; Madhuri Devdhar, et al; Sept 2007.
- "Postgraduate Medical Journal"; Management of Thryoid Disorders in Primary Care: Challenges and Controversies; C.H. Todd; 2009
Member Comments