Category B - full version without watermark 720x576 (check terms and conditions at www.teledesign.de) The embed version with watermark is free of charge. - Description: Like a butterfly with opened wings the thyroid is situated at the front side of the neck below the larynx and needs iodine. This micronutrient is the building block that is indispensable for the work of the thyroid gland -- which is the production, storage and release of thyroid hormones. These hormones provide for instance for the smooth running of the heart, the blood circulation, the musculature, the brain and the metabolism. The thyroid pulls the iodine out of the blood to produce the two hormones T3 and T4. However, sufficient iodine intake of the organism with the food is a prerequisite. Control of this "hormone factory" is achieved with messenger substances released by the pituitary gland. By this means the amount of hormones produced by the thyroid is accurately adjusted. A lack of iodine irritates the thyroid so much, that it expands and starts to hectically produce more and more cells. The sponge must be big enough to maximally use the little iodine for hormone production. The sponge gets bigger and bigger, a goiter develops. It is not always visible; often it grows inward and presses on the trachea and the esophagus. The constant growth of the thyroid leads to a loss of the control of the pituitary gland and other dysfunctions of the thyroid gland itself. The longer a goiter exists the larger the probability of nodule formation, of the development of tissue areas with uncontrolled growth. If there are scarred or knotty changes, physicians speak of cold or hot nodules. A cold nodule is scarred tissue that does not produce hormones any more. Sometimes it is indicative of a thyroid cancer. The hot nodules mostly are benign tumors, which may flood the body with an uncontrolled amount of hormones, though - one might virtually speak of intoxication. Every single cell of the body must work too much, eventually to exhaustion. Symptoms of this hyperfunction are: palpitations, nervousness, sleep disorders, tremor, excessive transpiration, hair loss, weight loss, diarrhea and irritable eyes. A hypofunction on the other hand leads to a slowing down of metabolic processes. The effects: tiredness, listlessness, constipation, dry skin and frail hail, weight gain, slowed thinking. In the elderly also hearing loss and depression may occur. Whether the thyroid produces too much or too little of hormones -- the organism will always be in a diseased state when it enlarges. Despite normal hormone production a goiter my compress the trachea, as can be seen on this radiograph, eventually also the esophagus or the vocal cord nerve, or it interferes with the carotid artery. A thick neck should not be ignored; a goiter is not just a cosmetic problem.