Introduction

Our body consists of various glands which are involved in metabolic reactions. There are two types of glands involved in it.

Exocrine glands
Endocrine glands

Endocrine glands are ductless in nature and their secretions directly enter into the bloodstream. Pituitary gland and thyroid gland are some of the examples of endocrine glands. Secretions of endocrine glands are known as hormones. Thyroid gland will be present in the neck region and it secretes thyroxine and triiodothyronine hormones. Hormones play a major role in body metabolism. Alteration in the level of hormones may result in dysfunction of metabolism. It may affect the cells, and cause disturbance in regular activities of a cell.

Thyroid gland : It is present in the neck region. The structure of this gland is like a butterfly. Thyroid gland hormones should be released into the bloodstream on a continuous and regular basis to maintain body functions normally.

Hypothyroidism is a condition in which the hormone levels are reduced due to various reasons.

[Picture source:

https://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/thyroid-gland-disorders/overview-of-the-thyroid-gland]

Causes

Inadequate amount of thyroid hormone in blood is termed as hypothyroidism. But it has various reasons. Primary hypothyroidism is the condition in which the levels of thyroid hormone is reduced. Secondary hypothyroidism is the condition in which the levels of thyroid stimulating hormone from the pituitary gland is reduced. Tertiary hypothyroidism is the condition in which the levels of thyrotropin releasing hormone from hypothalamus is reduced. Iodine deficiency is the main reason for primary hypothyroidism. It results in swelling around the neck region which is called a goiter.