The thyroid gland is a butterfly shaped endocrine gland that is normally located in the lower front of the neck. The function of thyroid gland is to make thyroid hormones, which are secreted in to the blood and then carried to every tissue in the body. Thyroid hormone plays a very important role in the body as use energy, stay warm and keep the brain, heart, muscles, and other organs working as they should. They help in regulation of growth and metabolism in the body. Thyroid hormones also help children grow and develop.
The thyroid’s hormones regulate vital body functions, including:

• Breathing
• Heart rate
• Central and peripheral nervous systems
• Body weight
• Muscle strength
• Menstrual cycles
• Body temperature
• Cholesterol levels and so many…

The thyroid gland is about 2-inches long and lies in front of your throat below the prominence of thyroid cartilage sometimes called the Adam’s apple. The thyroid has two lobes that lie on either side of your windpipe (trachea), and is usually connected by a strip of thyroid tissue known as an isthmus.
The thyroid needs iodine, to make its hormones. Iodide is a key substrate for thyroid hormone synthesis; a dietary intake 100 μg/day is required to maintain thyroid function in adults.
But if the thyroid makes too much hormone or not enough then it can cause some problems. Thyroid disorders can range from a small, harmless goiter (enlarged gland) that may need no treatment to life-threatening cancer. The most common thyroid problems due to abnormal production of thyroid hormones. Increased thyroid hormone production results in hyperthyroidism. Decreased hormone production leads to hypothyroidism.
Thyroid problems are often caused by autoimmune disorders, in which the immune system mistakenly attacks and destroys the body’s own cells. For example, an autoimmune disorder called Graves’ disease, a malfunction in the body’s immune system releases abnormal antibodies that mimic TSH can cause hyperthyroidism, while one called Hashimoto’s disease, inflammation of thyroid gland which impairs your thyroid’s ability to make thyroid hormone and results in hypothyroidism .Hashimoto’s thyroiditis is the most common cause of hypothyroidism.

Hypothyroidism