Overview of Thyroid
The thyroid is a butterfly-shaped gland in front of your neck. Along with the other glands of the endocrine system, it regulates the metabolic functions of the body by releasing thyroid hormones into the bloodstream.
Thyroid disorders can occur when there is too much or too less of thyroid hormone being produced by the gland. While too less of the hormones can slow down the metabolism, an excess of hormones can speed up the metabolism a lot. Although the hormonal imbalance causes a lot of disturbance, they can be well managed with medications.
Normal Functions of the Thyroid
The thyroid gland absorbs iodine from our diet and combines it with an amino acid known as Tyrosine to make the thyroid hormones T3 (triiodothyronine) and T4 (thyroxine). They are involved in regulating a variety of bodily functions such as:
- Body temperature.
- Body metabolism.
- Body weight.
- Growth.
- Brain development.
- Heart rate.
- Digestion.
- Energy levels.
- Muscle control.
- Mood.
- Bone maintenance.
Normal Range of Thyroid
Image Source : Mamma Health
Thyroid Disorders
Common disorders of the thyroid involve either over or under stimulation of the gland. Hence, depending on the type of disorder, the symptoms and treatment vary. The most common disorders of the thyroid include:
- Hyperthyroidism.
- Hypothyroidism.
- Goiter.
- Thyroid nodules.
- Graves' disease.
1. Hyperthyroidism
This is a disorder of the thyroid where the gland is overactive. In this condition, there is an overproduction of thyroid hormone. It is more common in women and those over 60 years old. An autoimmune disease known as Grave's disease is the most common cause, but there may be other reasons as well.
Causes
- Graves' disease.
- Toxic nodular goiter.
- Thyroiditis.
- Consuming more than recommended quantity of iodine.
- Taking a higher dose of synthetic thyroid hormone.
Symptoms
- Restlessness.
- Increased heart rate.
- Irritability.
- Sweating.
- Weight loss.
- Tremors.
- Thinning of skin, hair, and nails.
Diagnosis
- The doctor will recommend blood tests such as T4 and TSH. But, the values that are accepted to fall in the normal range vary from one doctor to another. So, it is not wise to start medications based on the blood test findings alone.
- So, apart from blood tests, the doctor will also conduct a physical examination to palpate the thyroid gland and feel for abnormal changes in texture. He will take into account your symptoms as well. Then, an ultrasound may or may not be required to confirm the diagnosis.
Treatment
- Antithyroid drugs: These drugs block the synthesis of the thyroid hormone by the thyroid gland. Different drugs are used commonly in different parts of the world. Most common antithyroid drugs include Carbimazole, Methimazole, and Propylthiouracil.
- Radioactive iodine: This therapy is suggested for those who cannot take medications or surgery. In this, a single dose of Iodine containing a radiation is given in the form of a capsule. Once it is swallowed, the thyroid glands take up the iodine, just like they do from food sources. But, since they contain a small amount of radiation, the thyroid cells get destroyed and they no longer produce as much iodine.
- Surgery: Depending on the reason for surgery, and cause of the problem, the entire thyroid gland or a portion of it would be removed surgically. In case a part of the gland is being removed, the rest of the gland takes over the functioning of the gland. If the entire gland is removed, the patient will have to take synthetic thyroid hormone replacement for the rest of his life.
2. Hypothyroidism
In this condition, the thyroid gland is underactive and there is an underproduction of thyroid hormone.
Causes
- Hashimoto's disease: It is a genetically inherited autoimmune condition where the body's defense cells confuse the healthy thyroid cells to be foreign bodies and attack them causing an inflammation of the thyroid gland. This reduces the thyroid function.
- Thyroid surgery for hyperthyroidism: In person's with hyperthyroidism, treatments such as radioactive iodine or thyroid removal surgery is performed to lower the thyroid functioning. This may sometimes cause the thyroid function to get permanently low leading to hypothyroidism.
- Radiation damage: Radiation therapy, as well as some medications used to treat certain types of cancer, can harm the thyroid cells and slow down the thyroid hormone production.
Symptoms
- Tiredness.
- Dry skin.
- Increased heart rate.
- Depression.
- Cold intolerance.
- Weight gain.
- Fatigue.
Diagnosis
- Blood tests such as T3, T4, and TSH would be ordered by the doctor to confirm the diagnosis of hypothyroidism if the patient presents with the above-mentioned common symptoms. In the case of hypothyroidism, there would be elevated levels of TSH and low levels of T3 and T4. So, the diagnosis is made based on the symptoms and blood test findings.
Treatment
- Synthetic thyroid hormone pills: The synthetic form of the hormone is known as Levothyroxine. Levothyroxine medicine is prescribed in different strengths according to the individual's need. It reverses the signs and symptoms of the disease. It is it to be taken lifelong. But, it is important to follow up with your treating doctor at regular intervals as the dosage will need to be adjusted from time to time.
3. Goiter
Goiter is a non-cancerous, abnormal enlargement of the thyroid gland. It is more common in women than in men. It is of different types based on the cause.
Causes
- Iodine deficiency: Iodine is necessary for the proper functioning of the thyroid gland. Lack of sufficient iodine in the diet causes thyroxine levels to go down and TSH to rise.
- Iodine excess: Excess of iodine from seafood, table salt, etc., can also ironically cause symptoms similar to iodine deficiency goiter.
Symptoms
- Neck swelling.
- Breathing difficulty.
- Swallowing difficulty.
- Cough.
- Hoarseness of voice.
Diagnosis
- Physical examination: The doctor may visualize or palpate a lump, nodule or swelling in the front of the neck during a routine examination. He may ask you to make swallowing actions if he suspects a swelling,
- Blood test for thyroid hormones and TSH: A goiter may be associated with an overactive or underactive thyroid, and the thyroid hormone and TSH levels will vary accordingly.
- Ultrasound of thyroid: An ultrasound uses sound waves to see the image of the thyroid gland on a screen. It may be ordered by the doctor if the doctor feels a lump on the thyroid or if the blood test findings are abnormal.
Treatment
- Radioactive iodine: In case of overactive thyroid, you will be asked to take radioactive iodine orally. The thyroid cells have an affinity for iodine and take up the iodine into the cells. The radioactive iodine destroys the thyroid cells and shrinks the gland in size. Depending on the extent of your symptoms and the swelling, the doctor may decide the dosage. This is now a more preferred treatment method than conventional surgery due to its safety and convenience.
- Surgery: Some goiters may be so large they can cause a difficulty with breathing and swallowing. Then surgery becomes necessary. The procedure may involve the removal of a portion or the entire gland depending on the individual case.
4. Thyroid nodules
Thyroid nodules are small, harmless, benign overgrowths that can develop on the thyroid gland. They can be solid or fluid-filled. They are mostly asymptomatic. Sometimes, some symptoms may develop such as the following.
Causes
- Iodine deficiency: Low dietary intake of iodine can cause nodular enlargement within the thyroid gland. Although only a small quantity of iodine is required by the body, it is very important for the proper functioning of the gland and production of hormones.
- Hashimoto's disease: It is an autoimmune disease where the body's protective cells turn against the body's own normal thyroid cells and destroy them. Hashimoto's thyroiditis is associated with an increased risk of development of thyroid nodules.
Symptoms
- Neck swelling.
- Breathing difficulty.
- Swallowing difficulty.
- Throat pain.
Diagnosis
- Physical examination: A thyroid nodule may be felt by the doctor by palpating outside your throat. He may ask you to make swallowing actions as that will make the nodule move more prominently.
- Ultrasound of thyroid: This is the best method to visualize the thyroid nodules on the screen. This will give us a picture of the number, size, and location of the nodules and also help differentiate them from cysts and cancerous swellings.
- Thyroid scan: Sometimes, if an ultrasound is not enough, a thyroid scan may be recommended where radioactive iodine is injected into a vein in your arm. After a while, a clear image is visible on a monitor, where it is possible to distinguish the nodules from normal cells as they take up more iodine than the surrounding cells. It is possible to differentiate between hot nodules (non-cancerous), as well as cold nodules (cancerous) by this test.
- FNAC (fine needle aspiration cytology): It is a type of biopsy where a small sample of cells is removed from the thyroid gland with the help of a needle. It is then sent away to a laboratory to be observed under a microscope to rule out any cancerous changes.
Treatment
Sometimes, no treatment is required. If symptoms are present, one of the following may be required.
- Radioactive iodine.
- Radiation therapy.
- Surgery.
5. Graves' disease
Graves' disease is an autoimmune disease where the body's immune cells mistake the thyroid cells to be foreign substances and attack them, causing overproduction of thyroid hormones.
Causes
- Hereditary.
- Stress.
- Pregnancy.
- Smoking.
Symptoms
- Bulged eyes are a prominent feature.
- Rest of the symptoms are the same as hyperthyroidism.
Diagnosis
- Physical examination.
- T4 and TSH.
- Radioactive iodine test.
Treatment
There is no cure for Graves' disease. Medicines cannot stop the immune system from continuing to attack the gland. But, symptoms can be managed with certain medications.
- Antithyroid medicines.
- Radioactive iodine.
- Beta blockers.
- Surgery.
Know the Facts
For more information consult a thyroid specialist online --> https://www.icliniq.com/ask-a-doctor-online/endocrinologist/thyroid
