Q: I am a 36-years-old female. I weigh 72 kg and my height is 5 feet 3 inches. I was diagnosed as suffering from hypothyroidism 2 years back. My TSH was 49.07mlu/ml. I was adviced to take Thyroxine 100mu. At present my TSH is 1.78ulu/ml but T4 is 13.2ug/dl. I read an article, which said that incidence of leucoderma increases with auto-immune diseases like diabetes, thyroid etc. I found this very disturbing. Can I get more information on this.

A:Hypothyroidism is a condition caused by a reduction in the amount of thyroid hormones produced by the thyroid gland (mainly T4 and a little T3) in response to a stimulus by the pituitary gland via another hormone called thyrotropin or thyroid stimulating hormone (TSH). The release of TSH by the pituitary gland depends on the stimulus provided to it by the thyrotropin-releasing hormone (TRH) which is secreted by the hypothalamus. Thus, hypothyroidism may be due to a thyroid disease (primary disease), a problem with the pituitary gland (secondary hypothyroidism) or something affecting the release of TRH from the hypothalamus (tertiary). It is the commonest hormone deficiency seen in clinical practice. Whenever there is a decrease in the blood level of T4, it stimulates the pituitary to produce more TSH which acts on the thyroid gland increasing the T3 production. Iodine deficiency and auto-immune thyroiditis are the 2 common causes of primary hypothyroidism. For reasons still not well understood, the body starts making antibodies to its own thyroid gland in auto-immune thyroiditis which cause progressive destruction of the gland resulting in hypothyroidism. Sometimes this may occur following delivery in women, some inflammatory diseases or viral fevers. What the underlying defect is that predisposes one to autoimmune thyroid disease is still unknown. Remission of hypothyroidism occurs in 5% to 11% of patients. Autoimmune thyroiditis is more prevalent in individuals with other autoimmune disorders and some genetic diseases. The development of the condition in an individual may be influenced by the genes inherited and the response of the immune system to certain triggers or environmental influences. If the diagnosis is made and treatment started early, the prognosis is excellent and patients lead a normal life. Hormone replacement is usually required life-long. Vitiligo is a condition in which white patches appear on the skin in different parts of the body due to the destruction of cells (melanocytes) that produce the pigment. Its cause is unknown and one theory says that it is likely due to an auto-immune process. The condition is seen a bit more often in individual's with auto-immune disorders but most people who suffer from vitiligo have no associated auto-immune disease.