Dr (Maj Gen) JKBansal, 
Vishist Sewa Medal, ChikitsaRatan, MD
WHO fellow Thyroidology, University of Southern California, USA
WHO fellow Endocrinology, University of Wales U.K.
ormer Head thyroid department INMAS Govt of India Delhi.
Thyroid Clinic 74 Mall Road, BehindD-3 Vasant Kunj, New Delhi
Senior Consultant, Thyroid & Diabetes Rockland Hospital, Qutab NewDelhi
Mob: 9910062437

Thyroid is a small, butterfly-shaped gland located in the front ofthe neck. The thyroid takes iodine from the blood and uses it to make theactive hormones thyroxine, also called tetraiodothyronine (T4), andtriiodothyronine (T3). These thyroid hormones deliver energy to cells of the body, burn calories and control heart beats.

I. Thyroid Disorders:

There are several different disorders that can arise due to overactive thyroid, or hyperthyroidism, and underactive thyroid or hypothyroidism or enlargement of the thyroid gland causing goitre. Thyroid problems include:

1. Hypothyroidism - when thyroid glanddoes not make enough thyroid hormones

2. Hyperthyroidism - when thyroid glandmakes more thyroid hormones than body needs

3. Goitre - enlargement of the thyroidgland due to thyroid nodules, thyroiditis, thyroid cancer.

II. T3,T4, TSH hormone tests: Blood tests can determine the amount of hormones produced by thyroid and pituitaryglands. If thyroid is underactive, the level of thyroid hormone will be low. Atthe same time, the level of thyroid-stimulating hormone (TSH) will be elevatedbecause pituitary gland tries to stimulate thyroid gland to produce morethyroid hormone. Goitre associated with an overactive thyroid usually involvesa high level of thyroid hormone in the blood and a lower than normal TSH level.

Antibodiestest:  A blood test mayconfirm the presence of antibodies indicating autoimmune thyroid disease.

Ultrasonography:  The images reveal the size of thyroid gland and whether the gland contains nodules that may not have been detected clinically.

Thyroid radionuclide uptake & scan:  Thyroid uptake & scans provide information about activity and size of thyroid.

Fine-needle aspiration cytology (FNAC)During afine-needle aspiration biopsy, ultrasound is used to guide a needle into thyroid to obtain fluid sample for testing. FNAC is useful to indicate whether lesion is benign or malignant.

III. Hypothyroidism:

One of the most common causes of hypothyroidism is the autoimmune disease called Hashimoto's disease, in which  anti thyroid antibodies gradually target the thyroid and destroy its ability toproduce thyroid hormone. Causes of hypothyroidism include:

1. Hashimoto's disease, an autoimmune disorder, where the body’s own immune system attacks thyroid tissue, leading to reduced thyroid hormone. 

  • Treatmentof Grave’s hyperthyroidism with radioactive iodine or by   thyroidectomy may lead to hypothyroidism.
  • Baby,born without a thyroid gland (congenital hypothyroidism);
  • Surgicalremoval of the thyroid gland as a treatment for thyroid cancer.

 Symptoms of hypothyroidism:

1. Fatigue or lack of energy

2. Dry, coarse skin

3. Dry, coarse hair

4. Sensitivity to cold temperatures

5. Heavy and/or irregular periods

6. Puffy tissues

7. Unexplained weight gain

8. Depression

9. Muscle cramps, muscle pain andtenderness

10. Slower than normal heart rate

11. Constipation

12. Infertility

13. Mental lethargy

14. Goitre

15. Decreased libido

Hypothyroidism poses a special danger to newborns and infants. A lack of thyroid hormonesin the system at an early age can result in cretinism (mental retardation) anddwarfism (stunted growth).  Infants need their thyroid levels checked routinely soon after birth. If they are found to be hypothyroid, treatment must begin immediately. In infants, hypothyroidism can be due to a pituitary disorder, defective thyroid or complete lack of the gland. A hypothyroid infant is unusually inactive and quiet, has a poor appetite and sleeps for excessively long periods of time.

Sub-clinical Hypothyroidism is quite common and almost impossible to diagnose clinically. There may be no symptoms, associated with this condition. It is important to make the correct diagnosis because once treatment is started it usually continues for life as it becomes very difficult to stop treatment to determine whether the original diagnosis was correct. The measurement of TSH in the blood helps to define even minor degrees of hypothyroidism.

Treating hypothyroidismThyroid hormone replacement with levothyroxine (Levothroid, Synthroid) will resolve the symptoms of hypothyroidism as well as slow the release of thyroid-stimulating hormone from pituitary gland.

IV. Hyperthyroidism:

When the thyroid gland becomes overactive and produces too much thyroid hormone, a person is said to be hyperthyroid. The most common cause of hyperthyroidism is the auto immunecondition known as Graves' disease, where thyroid antibodies target the gland and cause it to speed up hormone production. Hyperthyroidism occurs due to:

Graves' disease.This is an auto-immune condition and is the commonest cause of an overactive thyroid gland.

Toxic adenomas: Nodules develop in the thyroid glandand begin to secrete excessive thyroid hormones. A goitre may contain several of these nodules then it is called as multi-nodular toxic goitre.

Sub acute thyroiditis: This is where inflammation of the thyroid causes the gland to ‘leak’ excess hormones, resulting in temporary hyperthyroidism. The condition generally lasts a few weeks, but it may persist for months.

Hyperthyroidism- Signs and Symptoms:

1. Unexplained weightloss

2. Weight loss despite an increase in appetite

3. Irritability and nervousness

4. Muscle weakness and/or tremors

5. Irregular periods

6. Difficulty in sleeping

7. Compromised vision oreye irritation

8. Sensitivity to warmtemperatures

9. Heart palpitations orrapid heart beat

10. Frequent bowel movements or diarrhoea

11. High blood pressure

12. High heart rate

13. Excessive sweating

14. Excessive hair thinning

When the thyroid gland becomes enlarged due to diseases or tumours, it is referred as goitre. It can be associated with hyperthyroidism or with hypothyroidism. Goitre may be associated with normal levels of thyroid hormones. When goitre becomes very large, it can sometimes cause symptoms because it presses on adjacent structures such as the oesophagus and trachea. Symptoms that can occurrelated to a large goitre include problems with swallowing, shortness of breath, hoarseness. Some of the conditions that can cause goitre include:

1. Hashimoto's thyroiditis, a common autoimmune condition in which the body's immune response is directed against the thyroid gland, leading to inflammation of the thyroid

2. Iodine deficiency, is major cause of goitre

3. Graves' disease,another autoimmune disease, stimulates the gland to be overly active

4. Benign tumours (nodules) that may cause multi-nodular goitre

5. Thyroidcancers

VI. Message: 

If detected and managed, in early stage of onset, thyroid disorders are treatable. It is therefore advisable to report to thyroid specialist as soon as you suspect thyroid problem.