THYROID DISORDERS AND WHAT YOU SHOULD KNOW ABOUT IT

8 min


INTRODUCTION:

Thyroid disorders are one of the most common endocrine malfunction, commonly seen in children and pregnant women. Also, according to recent researches, almost 42 million people in India are affected by this disorder. Moreover, iodine deficiency is the most common cause of this deficiency. Further, it is very common in India. Also, in other countries like America, nearly 40 million people get affected by the disorders. Hence, the purpose of this article is to highlight about thyroid, its various types, diagnosis, treatment, and preventive measures of the diseases.

ANATOMY OF THYROID GLAND:

  • Before moving into the details of the disorders, we need to know about the anatomy of the gland.
  • Firstly, it’s a butterfly shaped gland located in the neck.
  • This is the second largest endocrine glands in our body. And also, it weighs between 15-25 g in adults.
  • Moreover, it’s a two lobed structure (contains two lobes) located in the base of the neck, below the wind pipe.
  • The two lobes of the glands are joined together by a narrow isthmus, located on either side of the trachea just below the larynx.
  • The two lateral lobes form the main bulk of the gland, and also sometimes additional lobe called pyramidal lobe may be present.
  • Moreover, this pyramidal lobe may arise from the isthmus.
  • Further, this gland is capable for enormous growth when stimulated intensely over a long period of time.

THYROID HORMONES:

Firstly, the hormones are classified into three types namely:

The hormonesFunction
THYROXINE (T4)Firstly, this makes up 90% of the hormone secreted by the gland. Moreover, it is not a biologically active form of the hormone but serves as a prohormone. Subsequently, T4 will get transformed into T3 in the tissues.
TRIIODOTHYRONINE (T3)T3 constitutes about 9% of the hormone secreted by the gland. On the other hand, T3 is four times more potent than T4.
REVERSE (rT3)To clarify, this represents about 1% of the hormone secreted by the gland and it’s biologically inactive.

THYROID-STIMULATING HORMONE (TSH):

TSH is a glycoprotein. Further, it increases the secretion of the hormones by accelerating the mechanism. And also, it’s responsible for hyperplasia (increase in the size of the gland) and hypertrophy (reduction in the size of the gland). Moreover, this improves the vascularity of the gland. Hence, the production of TSH is by a feedback mechanism.

Firstly, the normal level of TSH in women is 0.5-5.0 mlU/L. Further, the level of TSH will be fluctuating during menstruation, pregnancy due to excess production of estrogen

MECHANISM OF THYROID PRODUCTION:

  • Firstly, the hormone is produced by a mechanism called negative feedback mechanism. Further, it’s controlled by the hypothalamus and anterior pituitary gland.
  • Consequently, the neurons in the hypothalamus secrete thyroid releasing hormone (TRH). This further stimulates the anterior pituitary to secrete TSH. 
  • Above all, the anterior pituitary gland stimulates Thyroid stimulating hormone (TSH) . Consequently, TSH initiates the production of Thyroxine (TH) .
  • TSH binds to the epithelial cells of the the gland and further stimulates the production of the hormone.
  • Therefore, the T3 and T4 are produced by the gland and affect the metabolism of the body.

GOITRE:

Firstly, goitre refers to an abnormal increase in the size of the thyroid gland. It also denotes the functional status of the gland

STATE OF THYROID IN THE BODYLEVEL OF THE HORMONE
Euthyroid stateThe normal level of the hormone.
HypothyroidismLow level of the hormone.
HyperthyroidismIncreased level of the hormone.

TYPES OF GOITRE:

TYPE OF GOITRESTATE OF THE HORMONE
SIMPLE GOITREDeficient levels of the hormone
ENDEMIC GOITREOccurs due to lack of iodine
NON-TOXIC GOITRE/ SPORADIC GOITREUnknown cause
MULTINODULAR GOITREOccurs due to multiple nodes

GOITROGENS:

Firstly, food that inhibits the production of the thyroid gland is called goitrogens. To clarify, these include food like broccoli, cauliflower, Brussel sprouts, cabbage, radishes, canola, etc.

NORMAL LEVELS:

HORMONE OR LEVELUNITS
TSH 0.5-5 international units (IU)
Normal iodine levels100-200 µg/day

TYPES OF THYROID DISEASES:

The disorders are classified into the following types such as:

  • Hyperthyroid
  • Hypothyroid
  • Thyroid carcinoma

HYPERTHYROID:

FIrstly, it is an increased secretion of the hormone. Further, more commonly men and women between 20-40 years get affected.

SYMPTOMS:

  • Brittle hair (to clarify, fine hair or extremely thin hair) or hair loss
  • Bulging eyes (starring look)
  • Also, increase in size of the gland and liver
  • Increased sweating
  • Abnormal heart rhythms
  • Increased appetite
  • Tremors (to clarify, excessive shaking of hands)
  • Goiter
  • Nausea, vomiting, diarrhea
  • Irregular mensturation
  • Brittle nails
  • Finally, unintentional weight loss

CAUSES:

The causes for hypothyroidism include,

  • Graves’ disease
  • Thyroiditis
  • Overactive thyroid
  • Likewise, increased thyroid hormone medicine

GRAVES DISEASE:

Graves’ disease is also called toxic goitre or thyrotoxicosis. Consequently, this is the most common cause of hyperthyroidism. This is an autoimmune disease due to the development of thyroid-stimulating antibodies (TSAb) against the TSH receptors.

Meanwhile, it’s characterized by an increase in basal metabolic rate (BMR), weight loss, increased heat production, excessive sweating, increased pulse rate, goitre (swelling of the gland). The patient has a starring look due to eyelid retraction, bulging of the eyeballs.

THYROIDITIS:

Firstly, inflammation or swelling of the gland is called thyroiditis. And also, there are different types of thyroiditis they include:

TYPE OF THYROIDITISCHARACTERISTICS AND SYMPTOMS
Silent or painless thyroiditisThis usually occurs after Hashimoto’s thyroiditis. Further, it’s more common in women.
Postpartum thyroiditisThis type usually occurs in women for a shorter period of time. And also seen in women after delivery.
Radiation-induced thyroiditisThis type is usually caused by external radiation. Moreover, radioactive iodine is used as a treatment option for hyperthyroidism. Sometimes, this may result in this type of thyroiditis.
De-Quervain’s thyroiditisAlso called subacute thyroiditis. Further, it’s a painful condition caused by a virus. Most frequently patients have fatigue, low-grade fever, the pain can be radiating to the jaws, ears, chest, etc
Overactive thyroiditisThe over-production or excess production of the hormone results in an overactive thyroid. Hence, high levels of hormones are released into the body.
Increased thyroid medication Firstly, increased consumption of thyroid medicines results in this type of hyperthyroidism.
Hashimoto thyroiditisThe most common cause for thyroiditis. Also, it’s more common in women than men. To clarify, it is an autoimmune disorder caused by anti-thyroid antibodies.

HYPOTHYROID:

Hypothyroidism is caused by reduced levels of circulating thyroid hormones in the blood.

ETIOLOGY:

Hypothyroidism can be primary or secondary

BASIC TYPE OF HYPOTHYROIDISM CAUSE
Primary hypothyroidismDisorder of the gland
Secondary hypothyroidismCaused by diseases of anterior pituitary and hypothalamus

TYPES OF PRIMARY HYPOTHYROIDISM:

TYPE OF HYPOTHYROIDISM OTHER NAMES CHARACTERISTICS
Cretinism Infantile hypothyroidism The deficiency occurs during the first year of life. And also, characterized by mental retardation, marked growth retardation, pot belly, protruded tongue, dry skin, flat nose, sparse hair, etc.
Myxoedema Adult hypothyroidism It’s characterized by tiredness, sudden weight gain, decrease in body heat production, causes intolerance to cold, and decrease sweating.
Further, thick dry skin (toad skin), sparse hair, nonpitting oedema, constipation, and anaemia.

THYROID CARCINOMA:

Firstly, cancer affecting the gland is termed thyroid carcinoma. Further, the cells in the gland undergo mutations. Therefore, the mutation allows the cells to grow rapidly and multiply. Consequently, this results in the spreading of the nodes leading to cancer.

TYPES OF CARCINOMA:

TYPE OF CANCERCHARACTERISTICS OF CANCER
PAPILLARY THYROID CANCERMost common type. Moreover, this occurs from the papillary cells of the gland. Further, any age group gets affected.
FOLLICULAR THYROID CANCERFirstly, this type arises from follicular cells of the gland. Further, Hurthle cell cancer is one of the aggressive types of follicular thyroid cancer.
ANAPLASTIC THYROID CANCERFirstly, it’s a rare type. Moreover, occurs in older age group people. Further, the cells grow rapidly and it’s difficult to treat.
MEDULLARY THYROID CANCERThis type usually begins in the cells called C cells. Further, these C cells produce a hormone called calcitonin. Hence, the increased levels of calcitonin in the blood result in this type of cancer.

INVESTIGATIONS OF THYROID:

TESTPURPOSE OF THE TEST
Thyroid function testThis function test is used to detect hormones such as T3, T4, and thyroxine levels in the blood.
Autoantibody titrePresence of autoantibody such as TPO. Further, this indicates Grave’s disease.
Isotope scanUsed to detect thyroid cancer and to assess the spread of cancer. Further, isotopes are used in this scan
FNACIt is a biopsy diagnostic test. Further, the cells are removed from the gland and assessed histologically. Also, cancer types can be detected in this test.
USGMost importantly, it uses sound waves to take pictures of the glands.
CTTo clarify, it’s a noninvasive diagnostic scan used to detect the soft tissues more accurately.
MRI Used to detect detailed images of the hard and soft tissues.

TREATMENT:

  • The treatment should be planned in order to eliminate the underlying cause.
  • Also, Levothyroxine (75 mcg) is the drug of choice to treat hypothyroidism . Hence, after dosage stabilization, should be monitored for 6 months.
  • Also, anti thyroid drug are given
  • For thyroid cancer, either total removal of entire thyroid gland, or partial removal of thyroid gland is performed. Further, based on the involvement this surgery is performed.
  • Also, radioactive iodine therapy is given after thyroidectomy.
  • Further, chemotherapy reduce the chemicals in the cancer cells.
  • And also,targeted drug therapy usually given for thyroid cancer cases.
  • Further, supportive care can be given during thyroid radiation therapy, thyroid surgery etc.

CARE MEASURES :

  • There are no such diet to follow for thyroid patients. Meanwhile, you can divide your day into five parts.
  • And also, consume fruits and vegetables as small meals along with your regular food.
  • Most importantly, follow the split diet plan. Hence to increase the consumption of fruits and vegetables everyday in your diet.
  • Add up more proteins in your diet such as beans, eggs, fishes, pulses, legumes etc
  • Decrease dietary consumption.
  • Also, quit smoking. Further, smoking affects thyroid patients badly.
  • Also, drink plenty of water.
  • Above all, practice yoga for thyroid. There are certain yoga specifically for thyroid . Further, this plays a very important role in management of thyroid.

CONCLUSION:

To sum up, thyroid diseases are the most common auto-immune endocrine disorders affecting women and men. Hence, with proper medication and lifestyle thyroid can be maintained.


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Dr Shalini S.G
I am a dental surgeon. I love travelling and listening to music and a passionate person in research and doing lots of presentation. My area of interest is pathology, diagnosis and forensics.