Thyroid tumors can cause or result in hyperthyroidism. Hot nodules are those that produce significant quantities of thyroid hormone, and the increased elevation of thyroid hormone in the blood may be detected by blood tests. Cold nodules are also called non-functioning nodules. When a nodule is a cold nodule, the thyroid hormone level in the blood may test normal, so the patient may not have symptoms of thyroid disease. Hypothyroidism involves the production of too little thyroid hormone.
Hypothyroidism is the insufficient synthesis of the thyroid hormone.
This can cause a variety of health problems, including fatigue, weight problems, lethargy, and impairment of memory and mental function. This can lead to goiter, or enlargement of the thyroid gland. Untreated hypothyroidism can advance with increasing loss of mental function and physical energy, and in extreme cases can result in coma and death. Very young children are at higher risk of irreversible damage from untreated hypothyroidism. If hypothyroidism occurs in the first two years of life without prompt treatment, the afflicted child can develop irreversible brain damage.