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Hypothyroid Levels

Hypothyroid levels are the tools which helps to differentiate diagnosis of hypothyroidism,caused from different origin.

In United States,the incidence of hypothyroidism is 1-2% in people aged below50.In people aged above 70 years,2-4%cases of  hypothyroidism are in average to severe form. Sub clinical hypothyroidism, occurs in about 10 percent.

Hypothyroid Levels

In Congenital Hypothyroidism ,hypothyroid levels are  measured in one drop of blood. In about 3500 births, one child seems to have congenital hypothyroidism.

The Third National Health And Nutrition Examination Survey(NHANESIII0 of 17,353 patients showed increased levels of TSH in the U.S.

The Third National Health and Nutrition Examination Survey (NHANES III) of 17,353 patients reflecting the US population reported hypothyroidism . The study  by Framingham shows, hypothyroid levels( TSH)> 10mU/L in 5.9% of women and 2.4% of men. Laboratory findings : In most of the healthy patients, TSH values ranges from 0.5- 1.5mU/L.Hypothyroid levels ( TSH levels) are increased in patients with primary hypothyroidism and free  levels are  normal.In the initial stages, hypothyroid levels are:

• Low T3 levels
• Normal to low T4 levels           
• TSH levels are increased             

TSH levels are highest in evening and lowest in the afternoon.
           
The thyroid antibodies such as TPO antibodies and anti-Tg are helpful in finding the cause of hypothyroidism. Hashimoto's thyroiditis is diagnosed with anti-TPO antibodies.

If free T4 tests are unavailable or unreliable, a free thyroxine index (FTI) is better indicator of the levels of free hormones. The free thyroid hormone levels can be estimated by two methods : (a) by calculating the percentage of available thyroid hormone binding sites (also called T3 resin uptake)  or (b) by measuring the concentration of thyroxine-binding globulin (TBG). The FTI is the product of the T3 resin uptake and total T4 levels.

In severely ill patients with non-thyroid disease , TSH secretion is decreased and T4 levels are decreased while T3 levels are markedly decreased. In such patients, the primary aberration is the decreased conversion of T4 to T3, that is, hypothyroid levels.