Thyroid: Types, Symptoms, Diagnosis and Treatment

Thyroid has essential roles to manage various metabolic activities and growth all through the body.Thyroid uses iodine to deliver essential hormones.

August 21, 2017

Thyroid has essential roles to manage various metabolic activities  and growth all through the body. Thyroid uses iodine to deliver essential hormones.

What is Thyroid and How the Gland Works?

The Thyroid is a butterfly-formed organ in the front of the neck. This organ is situated beneath the Adam's apple wrapped around the trachea (windpipe). A thin region of tissue in the organ's center, known as the isthmus, joins the two thyroid flaps on each side. Thyroid has essential roles to manage various metabolic activities  and growth all through the body.

Thyroid uses iodine to deliver essential hormones. Thyroxine, otherwise called T4, is the essential hormone delivered by the organ. After conveyance by means of the circulatory system to the body's tissues, a little segment of the T4 discharged from the organ is changed over to triiodothyronine (T3), which is the most biologically active hormone.
The function of the thyroid gland is controlled by a feedback mechanism involving the brain. When thyroid hormone levels are low, the hypothalamus in the brain produces a hormone known as thyrotropin releasing hormone (TRH) that causes the pituitary gland (located at the base of the brain) to release thyroid stimulating hormone (TSH). TSH stimulates the thyroid gland to release more T4.

The pituitary gland and hypothalamus can also affect thyroid function and cause thyroid problems as the thyroid gland is controlled by the pituitary gland and hypothalamus.

Types of Thyroid Disease:


The most widely recognized thyroid issues include abnormal production of thyroid hormones. An excessive amount of thyroid hormone brings about a condition known as hyperthyroidism.


Inadequate hormone generation leads to hypothyroidism.


Enlargement of the thyroid gland is called Goiter.A goiter might be related with hypothyroidism, hyperthyroidism, or ordinary thyroid function.

Thyroid Nodules:

Thyroid nodules are lumps or abnormal masses within the thyroid. Nodules can be caused by  cysts, tumors, or cancers of the thyroid.

Thyroid Cancer:

Thyroid cancer is more common in women then man.There are different kinds of thyroid cancer, depending upon the specific cell type within the thyroid that has become cancerous.

Symptoms of Hypothyroidism:

Typical symptoms of hypothyroidism are abnormal weight gain, tiredness, constipation, heavy menstrual bleeding, hair loss, cold intolerance, and a slow heart rate.

Causes of Hypothyroidism :

  • Hashimoto's thyroiditis ,an autoimmune condition that causes inflammation of the thyroid gland.
  • Acute thyroiditis and postpartum thyroiditis, causing  inflammation of the thyroid gland.
  • Thyroid hormone resistance.
  • Surgical removal or radioablation of the thyroid.

Symptoms of Hyperthyroidism:

Hyperthyroidism  symptoms including weight loss, increased appetite, insomnia, decreased tolerance of heat, tremor, palpitations, anxiety and nervousness. In some cases it can cause chest pain, diarrhea, hair loss and muscle weakness

Causes of Hyperthyroidism :

  •     Graves' disease
  •     Toxic multinodular goiter
  •     Thyroid nodules that overexpress thyroid hormone known as "hot" nodules
  •     Excessive iodine consumption

Diagnosis of Thyroid Disease :

  • Thyroid function tests is done to measure the thyroid hormones T3 and T4, as well as the measurement of TSH. This may result in hyperthyroidism (high T3 and T4), hypothyroidism (low T3, T4), or subclinical hyperthyroidism (normal T3 and T4 with a low TSH).
  • TSH levels are considered the most sensitive marker of thyroid dysfunction. If the cause of hypothyroidism is due to insufficient TRH secretion, the result will not always be accurate,. In such cases a TRH stimulation test, in which TRH is given and TSH levels are measured at 30 and 60-minutes after, may be conducted.
  • T3 and T4 can be measured directly. However, as the two thyroid hormones travel bound to other molecules, and it is the "free" component that is biologically active, free T3 and free T4 levels can be measured.T4 is preferred, because in hypothyroidism T3 levels may be normal. 
  • Ultrasound of the thyroid may be used to determine whether structures are solid or filled with fluid, which helps to differentiate between nodules, goitres and cysts. It may also help differentiate between malignant and benign lesions.

Treatment of Thyroid Disease :

Hypothyroidism is dealt with substitution of the hormone thyroxine or levo thyroxine. This is normally given on daily basis as an oral supplement, and may take half a month to end up effective.Some reasons for hypothyroidism, for example, Postpartum thyroiditis and Subacute thyroiditis might be transient and take a break, and different causes, for example, iodine insufficiency can be made do with dietary supplementation.

Treatment of hyperthyroidism may include medicines that suppress thyroid function such as propylthiouracil, carbimazole and methimazole.

Radioactive iodine-131 can be used to destroy thyroid tissue. Radioactive iodine is selectively taken up by the thyroid, which after some time destroys the cells involved in its uptake. Surgery to remove the thyroid can sometimes be performed as a transoral thyroidectomy, an insignificantly obtrusive methodology.There is high risk of damage to the parathyroid glands and the nerves controlling the vocal cords if surgery is taken place.
If the entire thyroid gland is removed, hypothyroidism will naturally result, and thyroid hormone replacement therapy will be needed.