Our body is made up of organs, tissue, muscles, and glands that produce various types of hormones.
There are two types of glands in our body, endocrine, and exocrine glands.
Endocrine glands produce hormones that are carried by the circulatory system to a number of cells in our body.
One such gland produces thyroid hormone. This article discusses thyroid hormones, their secretion, and diseases associated with the gland and hormone.
Thyroid Hormone
Hormones are travel through the blood to other cells of the body. There are two types of transportation I.e. transport of water-soluble hormone and transport of steroid and thyroid hormones.
Endocrine hormones affect different types of cells in our body. For example,
- The pituitary gland produces growth hormones that cause growth in most parts of our body.
- Thyroxin from the thyroid gland increases the rate of many chemical reactions in almost all the body’s cells.
- Cortisol is produced by the adrenal cortex and performs multiple metabolic functions for controlling the metabolism of proteins, carbohydrates, and fats. It has also anti-inflammatory effects.
The thyroid gland is located immediately above the larynx, on each side of and interior to the trachea.
It is one of the largest endocrine glands weighing from 15-20gms in adults.
The thyroid secretes two major hormones;
- Thyroxine
- Triiodothyronine
Commonly known as T⁴ and T³ respectively.
Moreover, both of these hormones increase the metabolic rate of the body.
Thyroid secretion is controlled primarily by thyroid-stimulating hormone (TSH) secreted by the anterior pituitary gland.
The thyroid gland produces calcitonin, which is involved in calcium metabolism.
Synthesis and Secretion
About 93% of metabolically active hormones secreted by the thyroid gland is thyroxine and 7% is triiodothyronine.
These two hormones differ in rapidity and intensity of action but the function of these two hormones is qualitatively the same.
Differences in the TSH levels can lead to an overactive or underactive thyroid gland and can lead to thyroid problems.
Formation
Normal quantities of thyroxine are formed when we ingest iodine, about 50mmg in form of iodides. Common table salt is iodized to prevent iodine deficiency.
If the body doesn’t produce a sufficient amount of thyroxine hormone, he\she may be suffering from hyperthyroidism or hypothyroidism, thyroid disease.
This is an Autoimmune disease.
When your immune system attacks its own healthy cells, it leads to an autoimmune disease. In such a case, there is inflammation of the thyroid gland which results in changes in the thyroid functions.
Hyperthyroidism: This is a condition in which an overactive thyroid gland is producing an excess amount of thyroid hormones.
Hypothyroidism: In this condition, the underactive thyroid gland, is not able to produce enough hormones.
Causes of Thyroid
There are a number of reasons that cause hyperthyroidism or hypothyroidism.
These reasons are as follows :
-
Thiocyanate ions Decrease Iodide Trapping
The high concentration of Thiocyanate can cause inhabitation of iodide transport into the cell i.e. inhabitation of iodide trapping mechanism.
It prevents thyroglobulin from becoming iodinated and therefore from forming thyroid hormones.
This deficiency leads to increased secretion of TSH which causes an overgrowth of the thyroid gland.
-
Iodides in High Concentration
When iodides are present in high concentration most activities of the thyroid gland decreases. As a result the rate of iodination of tyrosine to form thyroid hormone decreases.
Because iodides in high concentration decrease all phases of thyroid activity, this somewhat decreases the size of the thyroid gland.
Hyperthyroidism
You get hyperthyroidism when there is an excess amount of thyroid hormone in your body.
As a result, you will start to experience thyroid symptoms.
Hypothyroidism
You get hypothyroidism when there is less amount of thyroid hormone in your body.
Hence, you will also witness some thyroid symptoms written below.
Symptoms of Hyperthyroidism
Thyroid Symptoms of hyperthyroidism are as follows;
- A high state of excitability
- Intolerance to heat
- Increased sweating
- Extreme weight loss
- Varying degrees of diarrhea
- Muscle weakness
- Nervous ness and psychic disorders
- Extreme fatigue
- Inability to sleep
- Tremor of hands
Most people with hyperthyroidism exhibit a certain degree of protrusion of the eyeballs. This condition is known as exophthalmos. Studies suggest that this condition occurs in about one-third of patients with hyperthyroidism.
In some cases when this becomes severe, the eyeball protrusion stretches the optic nerve, eventually damaging the vision.
Eyes protrude because of swelling of retro-orbital tissues and preventative changes in the extraocular muscles. In patients with immunoglobulins that react with the eye, muscles can be found in the blood and are usually high in patients with hyperthyroidism.
This condition is usually greatly amelio-related with the treatment of hyperthyroidism.
Causes of Hyperthyroidism
In hyperthyroidism, the thyroid gland is increased to two or three times its normal size.
The antibodies that cause hyperthyroidism occur as a result of autoimmunity that has developed against thyroid tissue.
Localized adenoma (a tumor) that develops in the thyroid tissue and secretes large quantities of thyroid hormone is also the cause of hyperthyroidism.
Diagnostic Tests
The most accurate diagnostic test for hyperthyroidism is the direct measurements of the constitution of free thyroxine in the plasma.
Seek immediate medical advice. You may also get the following tests:
- The basal metabolic rate is usually in excess of +30 to +60 in severe hyperthyroidism.
- Radioimmunoassay measures the concentration of TSH in Plasma. In the usual type, anterior pituitary secretion of TSH is completely suppressed by a large amount of circulating thyroid and triiodothyronine that there is no plasma TSH.
- The concentration of TSI is measured by radioimmunoassay. This concentration is usually high in thyrotoxicosis but low in thyroid adenoma.
Treatment
The treatment of hyperthyroidism is as follows:
The surgical removal of thyroid glands:
Before the operation propilethyoracil is given until the basal metabolic rate of the patient has returned to normal.
You get a high concentration of iodides for one to two weeks.
This causes the glands to recede in size and their blood supply to diminish.
Radioactive iodine:
The hyperplastic, toxic thyroid gland absorbs 80 to 90 percent of injected iodide.
In case this iodine is radioactive, it destroys most of the secretory cells of the thyroid gland.
Usually, the patient gets five millicuries of this iodine.
Moreover, your doctor re-assesses your condition after several weeks.
Hypothyroidism
In general, hypothyroidism is the opposite of hyperthyroidism.
But there are a few physiological mechanisms that are peculiar to hyperthyroidism.
Symptoms of Hypothyroidism
Thyroid symptoms of hypothyroidism are as follows;
- Fatigue and extreme somnolence
- Excessive sleep for up to 12 to 14 hours a day
- Extreme sluggishness
- Slow heart rate
- Decrease cardiac output
- Decreased blood volume
- Sometimes increased body weight
- Mental sluggishness
- Failure of many tropic functions of the body
- Depressed growth of hair
- Scaleliness of the skin
- Also the development of frog-like husky voice
The thyroid symptoms of hypothyroidism and hyperthyroidism are not exactly the same.
Hence, it helps your doctor to distinguish between the thyroid condition you have.
Causes of Hypothyroidism
Hypothyroidism initiates by autoimmunity by the thyroid gland, thyroid inflammation, dietary iodine deficiency, idiopathic none toxic colloid goiter, etc.
The common causes of hypothyroidism are as follows:
Thyroiditis is thyroid inflammation. It causes progressive deterioration and finally fibrosis in the gland. Eventually, it results in the diminished or absent secretion of thyroid hormone.
- Dietary iodine deficiency:
Endemic colloid goiter is caused by dietary iodine deficiency and refers to an enlarged thyroid gland.
A lack of iodine prevents the production of thyroxine and triiodothyronine.
This causes the pituitary gland to release large quantities of TSH levels.
The TSH then stimulates the thyroid cells to release more amount of thyroglobulin colloid into the follicles and the gland grows larger and larger.
It may increase to 10 to 20 times in normal size.
- Idiopathic non-toxic colloid goiter:
We may not know the exact cause of the enlarged thyroid gland in patients with idiopathic colloid goiter.
However, some patients show signs of mild thyroiditis.
Furthermore, this leads to increased TSH secretion and progressive growth of noninflamed portions of the gland.
Also, some foods contain goitrogenic substances that have a type of antithyroid activity that leads to TSH-stimulated enlargement of the thyroid gland.
Moreover, you can find them in some varieties of turnips and cabbages.
Diagnostic Tests for Hypothyroidism
Your doctors diagnose hypothyroidism and hyperthyroidism with the same tests.
The free thyroxine in the blood is low. The basal metabolic rate in myxedema ranges between -30 and -50.
In addition, the secretion of TSH by the anterior Pituitary gland when a test dose of TRH is administered is usually increased.
Treatment
Your doctor advises daily oral ingestion of one or more tablets of thyroxine.
It maintains a steady level of thyroid hormone activity in the body.
Moreover, the effect of thyroxine on basal metabolic rate demonstrates that the hormone normally has a duration of action of more than one month.
Effects of Thyroid Hormone on Our Body
Thyroid hormone also affects various functions performed in our body.
Moreover, some of these health problems can be life-threatening and are as follows:
- Thyroid hormone has an effect on growth. It promotes the growth and development of the brain, bones, etc.
- In case you have a family history of thyroid disorder, consult your doctor and seek medical advice.
- Moreover, it affects the plasma and liver fats in our body. It maintains the concentration of cholesterol, phospholipids, and triglycerides in the plasma.
- Thyroid hormone also affects blood and cardiac operations as well as the circulatory operations in our body, thereby increasing blood pressure.
- It also affects body weight. As discussed above it can either cause an increase or decrease the body’s weight.
- Thyroid affects other endocrine glands.
- Additionally, it has effects on the central nervous system of the brain. It helps maintain the psychological balance of the human mind.
- Moreover, it has an effect on the function of the muscles. An increase or decrease in thyroid hormone can either make the muscles sluggish or vigor.
- Thyroid nodules are present in the glands. If the thyroid nodules make too much thyroid hormone, they can become benign and cause thyroid cancer.
- The thyroid hormone also affects the sexual functions of men and women equally.
In men, it can cause loss of libido and sometimes cause impotence.
Moreover, in the case of women, it can cause excessive and frequent menstrual bleeding, irregular periods, and sometimes amenorrhea.
Conclusion
The functioning of the endocrine glands is as important as that of other organs.
Some endocrine glands perform an important function as they produce hormones that are responsible for the functioning of other glands.
Moreover, you could experience muscle fatigue, sluggishness, sleep disorders, increase or decrease in weight in either of the cases of hyperthyroidism or hypothyroidism.
Usually, the doctor recommends blood tests that indicate whether a person has hyperthyroidism or hypothyroidism. In either of the cases, the doctor usually prescribes thyroxine to treat the disease.
Moreover, on daily basis, we should take a healthy diet with whole grains, fruits, vegetables, and lean meat. Excess use of salt or iodized salt should be avoided as it is one of the major causes of dysfunction of the thyroid gland and will cause any thyroid symptoms.
Hence, if you experience thyroid symptoms, book an appointment at REPC Dubai and let our doctors assess your condition thoroughly.
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