The thyroid gland is a butterfly-shaped organ positioned in the base of the neck, just above your collarbone. It is one of your endocrine glands and releases hormones that control metabolism—the way your body uses energy and many activities performed by the body.
Thyroid gland and its hormones
The thyroid gland releases hormones that regulate body functions like Breathing, heart rate, central and peripheral nervous systems, body weight, muscle strength, menstrual cycles, body temperature, cholesterol levels and much more. The 2 – inches long thyroid gland lies in front of your throat below the Adam’s apple medically known as the prominence of thyroid cartilage. The thyroid has two sides called as lobes that lie on either side of the windpipe which makes it look like a butterfly and is connected by strips of thyroid tissue known as an isthmus. Sometimes the isthmus is absent in few people and they have two separate thyroid lobes.
The thyroid gland is a part of the endocrine system, and is made up of glands that produce, store, and release hormones into the bloodstream. The two main thyroid hormones Triiodothyronine (T3) and Thyroxine (T4) are created from iodine and tyrosine. This hormonal activity is regulated by the thyroid-stimulating hormone (TSH). TSH is secreted from the anterior pituitary gland, which itself is synchronized with the hypothalamus that produces thyrotropin-releasing hormone (TRH). The hypothalamus signals the pituitary gland to notify the thyroid gland to produce more or less of T3 and T4 by increasing or decreasing the release of a hormone. These hormones then reach the body cells through the bloodstream.
Sometimes the T3 and T4 levels are low in the blood, and then the pituitary gland releases more TSH to notify the thyroid gland to produce more thyroid hormones. And if T3 and T4 levels are high, the pituitary gland releases less of TSH to notify the thyroid gland to slow the production of these hormones. It is very important that T3 and T4 levels are neither too high nor too low in the body. When the gland produces excessive amounts of T3 and T4 thyroid hormones, it is said to be hyperthyroidism and when it produces insufficient T3 and T4 thyroid hormones, it is said to be hypothyroidism.
Why maintaining right Thyroid levels is important?
The thyroid hormones regulate and maintain the metabolism of the body. It is very important to maintain the right amount of thyroid hormones in the body to help in the right functioning of almost all the organs. The hormones regulate a wide range of functions in the body pertaining metabolism, cardiovascular, developmental activities and other hormonal activities.
The thyroid hormones help in increasing the basal metabolic rate that affects almost all the body tissues. The thyroid hormones play a vital role in maintaining the appetite, absorption of substances, and intestinal functions. They help in the absorption in the intestine that in turn helps process the food faster, generation and uptake of glucose (Gluconeogenesis (GNG) is a metabolic pathway that results in the generation of glucose from certain carbohydrate and non-carbohydrate substances) and also digestion or breakdown of glucose. They also help in the breakdown of fats and maintain cholesterol levels in the body and increase the rate of secretion of cholesterol in the bile.
The thyroid hormones also help in increasing the rate and strength of the heartbeat by increasing the rate of breathing and intake of oxygen. This helps in increasing the blood flow in the body and maintaining the body temperature. Thyroid hormones play an important role during pregnancy. It is very important to maintain the right thyroid levels as they help in the development of the fetus brain maturation. It also helps in increasing the growth rate of young people and cells of their developing brain. Thyroid hormones help in maintaining sleep, thought process and sexual functions. Normal thyroid levels are very important to have regular menstrual cycles in women. To have all these functioning properly, it is very important to maintain the right level of thyroid hormones in the body. 97% of women suffer from thyroid problems and rarely very few men face it.
How is thyroid diagnosed?
Thyroid is diagnosed with the help of Thyroid Function test. This is a blood serum test taken either fasting or empty stomach or can be taken after food. The doctors will initially look for the typical symptoms in the patients before they advice for the thyroid blood test. Few of the symptoms are restlessness, fatigue, increased sweating, anxiety, insomnia, thin skin, hair loss, weight loss/gain, constipation, depression, weakness, slow heart rate and more. If the doctor finds these symptoms, he may suggest for a blood test to confirm thyroid function, and to check if the patient is suffering from Hyperthyroidism or Hypothyroidism.
During the procedure, the lab technician draws blood from the arm and sends it to the lab for testing. The components of the tests include T3, T4, and TSH commonly, but advanced tests include TPOAb (Thyroid Peroxidase Antibodies), TSI (Thyroid-stimulating Immunoglobulins), Tg (Thyroglobulin) and TgAb (Thyroglobulin Antibodies). Let us have a look on the normal reference ranges of these components deciding thyroid hormones:
|Thyroid test for hormones||Reference ranges|
|TSH (Thyroid Stimulating Hormone)||0.5 – 4.70 μgm/dl|
|T3 (Total Triiodothyronine)||80 -200 ng/dL|
|T4 (Total Thyroxine)||4.5-12.5 µg/dL|
|Free T4 (Free Thyroxine)||0.8-1.8 ng/dL|
|Free T3 (Free Triiodothyronine)||2.3- 4.2 pg/mL|
|TPOAb (Thyroid Peroxidase Antibodies)||0-35 IU/mL|
|TSI (Thyroid-stimulating Immunoglobulins)||0-1.3|
|Tg (Thyroglobulin)||No thyroid gland: 0-0.1 ng/ml.
Still have a gland: 0-33 ng/mL
|TgAb (Thyroglobulin Antibodies)||0-4.0 IU/mL|
On the basis of the results that show high or low TSH the doctor concludes on the thyroid diagnosis and suggests if the patient is suffering from Hyperthyroidism or Hypothyroidism. In most healthy individuals, a normal TSH value means that the thyroid is functioning normally.
- T4 circulates in the body in two forms, T4 protein bound and free T4. The free T4 fraction is the most important to determine how the thyroid is functioning, and Combining the TSH test with the FT4 accurately determines how the thyroid gland is functioning.
- T3 test is often useful in diagnosis of hyperthyroidism or to determine how severe the hyperthyroidism is.
- In Thyroid Antibodies test, two common antibodies that cause thyroid problems are thyroid peroxidase and thyroglobulin. Measuring these levels may help diagnose the cause of the thyroid associated problems.
- Thyroglobulin (Tg) is a protein produced by normal thyroid cells and also thyroid cancer cells. It is mostly used in patients who have had thyroid cancer surgery for monitoring them after treatment.
There are also non-blood test available like Ultrasound, Thyroid Scan and Radioactive Iodine uptake test to diagnose and find the cause of thyroid disease. The doctor can also find out if the patient is suffering from any thyroid associated diseases and problems.
What are the disorders associated with thyroid?
Thyroid is an important part of the whole body functioning and plays a vital role. There are several problems associated to thyroid gland dysfunction, they include
- Goiter – this is a noncancerous enlargement of the thyroid gland. Iodine deficiency in the diet is the most common cause of goiter worldwide. Goiter is associated with thyroid problems and often a symptom of hyperthyroidism. This is very common in women after the age of 40, although it can affect anyone at any age.
- Hyperthyroidism – when the thyroid gland is overactive and it produces too much of T3 and T4 hormone, the patient is said to have hyperthyroid. This is when the TSH value is low. The symptoms of hyperthyroidism include restlessness, nervousness, racing heart, irritability, increased sweating, shaking, anxiety, insomnia, thin skin, brittle hair and nails, muscle weakness, weight loss and bulging eyes (in Graves’ disease).
- Hypothyroidism – is when thyroid gland is underactive, and it can’t produce enough of its T3 and T4 hormones and the TSH value is higher. Less of thyroid hormone production leads to symptoms like fatigue, dry skin, and increased sensitivity to cold, memory problems, constipation, depression, weight gain, weakness and slow heart rate. In extreme cases this causes coma.
- Thyroid cancer – Thyroid cancer is the most common type of endocrine cancer yet very rare. Like other cancers, thyroid cancer also develops with the changes in the DNA. This is usually common among people who are exposed to radiation treatment of head, neck, or chest (especially during childhood).
- Thyroid nodules – these are basically the lumps formed by growth of mass on the thyroid gland. About 1% of men and 5% women have thyroid nodules that can be felt and about 50% of people have these nodules which are too tiny. These can even grow over time and lead to cancer.
The other diseases associated with thyroid are, Graves’s Disease (common cause of hyperthyroidism) and Hashimoto’s disease (also known as chronic lymphocytic thyroiditis, is the most common cause of hypothyroidism).
How can you prevent thyroid problems?
Thyroid is the hormone control centre for the whole body and the functioning of the entire body is regulated by the chemical balance of these hormones. The thyroid is known as your metabolic master because it controls every single cell in the body. Maintaining the thyroid ranges and keeping the hormonal activity normal is very important. Preventing hyperthyroidism or hypothyroidism is not really possible, but they can be regulated with the help of hormonal supplements that the doctors provide.
Few things you can do to prevent thyroid problems are, avoid starvation diets as they increase in cortisol and activates stress. A low calorie diet may cause damage and fasting can result in the reduction of T3 hormones in the body. Excessive exercise also reduces the activity of T4 and T3 blocking your thyroid hormone from getting into your cell. Thyroid gland is very sensitive to radiation, whether it’s from a dental X-ray, mammogram, MRI or general background radiation. Request for a thyroid shield when you take a dental X-ray and when you are being exposed to radiations for any treatments.
Above all this, if you have ever been diagnosed with grave’s disease or hashimoto’s disease, or had a family history of thyroid problems, only a preventive and regular blood check for thyroid hormones will help you maintain the thyroid hormones functioning properly and help in avoiding thyroid dysfunction. It is now very easy to have a preventive thyroid function test in Bangalore. Just reach out to BookMyScans and you can book an appointment with the diagnostic centers near you to take up this thyroid function blood test. While booking with BookMyScans, you can definitely save at least 50% on the cost of the thyroid test. BookMyScans partners only with labs that is approved and certified by ISO and NABL to assure you get the best quality thyroid function tests and technical competent accurate results. There is easy accessibility to the reports online and you can conveniently download your reports when needed. This will also help in maintaining the health records and prevent thyroid problems.
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