Relationship between TSH Levels and Hypothyroidism

Hypothyroidism is an endocrine disorder that is most common to females who are in their child-bearing years. This disorder can either be acquired or congenital. It can also be overt or subclinical. Hypothyroidism can also be further identified based on its site of abnormality. You may say that it is primary when the abnormality is due to thyroid level and secondary if the abnormality is hypothalami or pituitary.

Causes of Hypothyroidism

There are various causes of hypothyroidism. However, the most prevalent grounds are amiodarone-induced hypothyroidism, Hashimoto’s thyroiditis, postpartum thyroiditis and post ablative or postsurgical hypothyroidism. Below are some of the other causes of hypothyroidism according to the site of abnormality.

Primary

·         Surgical removal

·         Therapeutic radio iodine or irradiation

·         Autoimmune diseases like atrophy thyroiditis and Hashimoto’s thyroiditis

·         Infiltrative process

·         Idiopathic atrophy

·         Defects in inherited enzyme

·         Iodine deficiency anemia

·         Agenesis

·         Postpartum

·         Postpartum

·         Excessive amount of iodide

·         After therapeutic or surgery radioiodine

·         Certain medication drugs like lithium, sorafenib, thalidomide, interferon alpha, amiodarone, sunitinib and aminoglutethimide.

Secondary

·         Diseases connected with the pituitary gland such as

o   Trauma

o   Infiltrative disorders

o   Therapeutic or surgery radioiodine and irradiation

o   Sheehan’s syndrome

o   Tumors

o   Genetic structures of pituitary hormone defects

·         Thyroid hormone Defiance

·         Hypothalamic disease

How are TSH Levels and Hypothyroidism related?

The thyroid stimulating hormone or TSH is very essential in determining the health status of your thyroid. It is a hormone that is produced by the pituitary gland. Production level of TSH varies in amount. The thyroid stimulating hormone serves as a stimulant that incites the thyroid gland to engender certain hormones. These thyroid hormones are known as T3 or triidothyronine and T4 or thyroxin. 

The health of the thyroid can be determined by checking the TSH level in the blood. Normal TSH level ranges from 0.4 to 4.0 mIU/L. TSH level  that  lies above the maximum normal value of 4.0 is considered high enough and thus results in hypothyroidism. High level of TSH happens when the pituitary gland overproduce TSH. Over production of TSH will tend to insulate the thyroid gland from producing T3 and T4. The TSH level that reaches 2.0 mlU/L increases the probability of developing hypothyroidism. This level is commonly referred to as sub-clinical hypothyroidism.