World Thyroid Day - 25th May
Eminent Author, Medical Biochemist and Scientist, Technical Education consultant.
AGD Biomedicals (Pvt) LTD. Andheri East, Mumbai.
World Thyroid Day is a global healthcare event intends to recognize thyroid disease burden, the experiences of patients and all those committed to the international study and treatment of thyroid disorders(1). Thyroid diseases are among the most prevalent endocrine disorders globally. Various studies on thyroid disease have projected that approximately 4.2 crore Indians are affected by it(2).. Epidemiological studies indicate that 1% of men and 5% of women have clinically detectable thyroid nodules and that the prevalence rises with age and in iodine-deficient communities(1,2). Overweight and Obesity are increasingly recognized as significant risk factors for the incidence and progression of thyroid cancer(7). Early detection of thyroid gland disease by routinely performed and fifth generation POCT-backed IVD laboratory tests enable prompt and effective treatment, which can prevent serious complications such as menstrual irregularities, decreased fertility, thyroid cancer, hypercholesterolemia, cardiovascular problems, weight fluctuations, iron deficiency anemia, and constipation(5). Thyroid disorders need significant healthcare expenditures due to their chronic nature and high frequency. It is possible to reduce the long-term expenses linked to complications and late thyroid disease stages by encouraging early diagnosis and adequate treatment(6).
NOTE:
Thyroid Research and Practice Medknow journal highlighted the lack of attention paid to thyroid disorders, and advocated inclusion of thyroid diseases in the list of non-communicable disease (NCDs) of public health importance(3).
Q1. What is the prevalence of thyroid diseases?
ANS: According to the National Family Health Survey (NFHS IV, 2021), the prevalence of self-reported thyroid disorders in India is about 2.2% in women and 0.5% in men in the age group of 15-49%(2, 9). Goitre due to iodine deficiency contributes to 2.72% of all sequelae of disease worldwide(1,2). Female gender and older age have been found to have significant association with hypothyroidism(3).
The prevalence of hypothyroidism is high, affecting approximately one in ten adults in the study population(3).
NOTE:
(A) Thyroid hormones are T3 (triiodothyronine) and T4 (Thyroxine). These are secreted by thyroid gland with response to feedback action of TRH (thyrotropin releasing hormone) secreted by hypothalamus, which stimulates secretion of TSH (thyroid stimulating hormone) by the pituitary gland.
(B) Thyroid hormones (T3 and T4) play very important role in maintaining homeostasis by regulating oxidative reactions, various metabolic reactions, cardiovascular functions and energy expenditure. They also play important role in the development of skin, muscles and bones. Thyroid hormones play a crucial role in the reproductive health of both male and female by impacting development of sex organs, sexual functions, menstrual regulation and fertility.
(C) The most prevalent thyroid disorders are hyperthyroidism, which is characterized by excessive thyroid hormone production and hypothyroidism, which is characterized by inadequate thyroid hormone production.
Interpretative table 1(5)
| SERUM | INTERPRETATION |
| T3: Increased. T4: Increased. Ultrasensitive TSH: Decreased |
Primary Hyperthyroidism |
| T3: Decreased. T4: Decreased. Ultrasensitive TSH: Increased |
Primary Hypothyroidism |
| T3: Normal. T4: Normal. Ultrasensitive TSH: Increased |
Subclinical Hypothyroidism |
| T3: Decreased. T4: Decreased. Ultrasensitive TSH: Decreased |
Secondary or Tertiary Hypothyroidism |
NOTE: Increased or decreased values of Thyroid Binding Globulin (TBG) influence serum levels of T3 and T4. Hence for true values of serum T3 and T4, serum free T3 and free T4 determinations are recommended.
Q2. What are the examples of primary thyroid diseases?
ANS:
(A) Iodine-deficiency Goiter (hypothyroidism)
(B) Grave’s disease (Autoimmune hyperthyroidism)
(C) Autoimmune thyroiditis (Hashimoto’s disease, hypothyroidism):
(D) Thyroid tumors
(E ) Myxedema (Hypothyroidism or hyperthyroidism)
(F) Thyroid cancer
(G) Thyroid bacterial infections
NOTE: Thyroid hormone secretion levels change in primary thyroid disease, when thyroid gland is affected, in secondary thyroid disease, when pituitary gland is affected and also in tertiary thyroid disease, when hypothalamus is affected. IVD laboratory tests are useful to diagnose fast and precisely a specific thyroid disease (Refer to Table1).
Q3. What are the symptoms of thyroid disorders?
ANS: Common hypothyroid symptoms include weight gain, slow heart rate, fatigue, low energy, constipation, inability to tolerate the cold, and dry skin. Common hyperthyroid symptoms include enlargement of the thyroid gland, anxiety, weight loss, irritability, increased heartbeats, inability to tolerate the heat, diarrhea, and enlargement of the thyroid(5).
Q4. What are the most common ‘Thyroid Function tests’ and how these are useful in the diagnosis of thyroid disease?
ANS: The following are the common ‘Thyroid Function Tests’: Serum T, T4 and TSH, along with a complete “Hemogram report’(5).
NOTE:
These tests are useful in the diagnosis of thyroid diseases mentioned in the Table 1 and the blood hemoglobin level of the patient along with other CBC parameters.
Q5. What is the importance of complete hemogram (CBC) in the management of thyroid disease?
ANS: A growing body of evidence suggests that iron-deficiency anemia (ID) may play a significant role in the pathogenesis of thyroid dysfunction. Studies currently published in the literature indicate a possible relationship between ID, thyroid function, and autoimmunity(8). Moreover, iron absorption in the small intestine tends to decrease in hypothyroidism, leading to further iron deficiency and bone marrow activity is suppressed leading to low production of red blood cells(5).
NOTE:
In patients with coexisting iron-deficiency anemia and subclinical hypothyroidism, anemia does not adequately respond to oral iron therapy(8).
Q6. What advanced IVD laboratory tests are required for the precise diagnosis of thyroid disease?
ANS: Serum: Free T3, Free T4, TBG (Thyroid binding globulin), Thyroglobulin, TRH (Thyrotropic hormone), TgAb (Antithyroglobulin antibodies), TPOAb (Antithyroid peroxidase antibodies), TSH-receptor antibodies,, Serum calcitonin (for tumors of C-cells of thyroid gland)(5).
Q7. What are the recent innovations in IVD laboratory tests that have significantly impacted the speed, precision and accuracy in the detection and management of thyroid disease?
ANS: Advances in the fifth generation point of care tests (POCTs) based on lateral immunochromatographic tests, advanced Enzyme-linked immunoassays (ELISA), advanced Microparticle Immunoassays (MEIA), Fluorescence Polarization Immunoassays (FPIA), Radiative Energy Attenuation (REA) assays and advanced Immunological analyzers based on MEIA, FPIA and REA. Advanced hematological analyzers are also extremely useful in the fast and accurate diagnosis and management of iron-deficiency anemia in thyroid diseases(5).
CASE STUDY 1
A 40-year-old female presented with lethargy, fatigue, weight gain, slow pulse rate, constipation and irregular uterine bleeding. The following were her clinical laboratory reports:
| PARAMETER | VALUE | NORMAL RANGE |
| T3 | 61 ng/dl | 86-187 ng/dl |
| T4 | 2.8 µg/dl | 4.5-12.5 µg/dl |
| TSH | 11.8 µIU/ ml | 0.3- 5.0 µIU/ ml |
Diagnosis
With reference to Interpretative table 1: Hypothyroidism
COMPLETE HEMOGRAM
| PARAMETER | VALUE | NORMAL RANGE |
| Hemoglobin | 5.5 g/dl | 12–16 g/dl |
| Total erythrocyte count | 2.1 X 1012/l | 4.3 ± 0.5 X 1012 /l |
| Total leukocyte count | 7,800 | 7.0 ± 3.0 X 109/l |
| Differential leukocyte count | ||
| Neutrophils | 68% | 40–75% |
| Lymphocytes | 30% | 20–45 % |
| Eosinophils | 1% | 1–4 % |
| PCV | 20.5% | 36–48% |
| MCV | 88.5 fL | 82–92 fL |
| MCH | 28.5 pg | 27–32 pg |
| MCHC | 33 % | 32–36 % |
| RDW- CV | 16.8 | 12–14 |
| Platelet count | 180 X 109 /l | 150–400 X 109/l |
| Stained peripheral blood smear Microscopic observations | ||
| Hypochromia | +++ | Normal cells |
| Microcytes | ++ | Normal cells |
Diagnosis
Hypochromic, microcytic anemia.
CASE STUDY 2
During routinely performed clinical laboratory tests; an apparently normal 28-year-old male student’s thyroid test report was as follows:
| PARAMETER | VALUE | NORMAL RANGE |
| T3 | 86 ng/dl | 86-187 ng/dl |
| T4 | 9.8 µg/dl | 4.5-12.5 µg/dl |
| TSH | 17.2 µIU/ ml | 0.3- 5.0 µIU/ ml |
Diagnosis
With reference to Interpretative table 1: Subclinical Hypothyroidism
Advise of an endocrinologist was recommended.
CASE STUDY 3
A 46-year-old male presented with weight loss, excessive sweating, irritability, palpitations, abnormal protrusion of eyes, fatigue and heat intolerance. The following were his clinical laboratory reports:
| PARAMETER | VALUE | NORMAL RANGE |
| T3 | 220 ng/dl | 86-187 ng/dl |
| T4 | 13.7 µg/dl | 4.5-12.5 µg/dl |
| TSH | 0.2 µIU/ ml | 0.3- 5.0 µIU/ ml |
Diagnosis
With reference to Interpretative table 1: Hyperthyroidism
Q8. How do early detection of thyroid disease impact patient outcomes and overall healthcare costs?
ANS: Thyroid problems involve significant healthcare expenditures due to their chronic nature and high frequency of medical examinations and blood tests. It is possible to reduce the long-term expenses linked to complications and late disease stages by encouraging early diagnosis and adequate treatment regime(6).
References
(1) American thyroid association: Vision and Mission (2025)
(2) Government of India Press Information Bureau (2022).
(3) Kalra Sanjay, Unnikrishnan Ambika Gopalakrishnan, Sahay Rakesh. The global burden of thyroid disease. Thyroid Research and Practice 10(3):p 89-90, Sep–Dec 2013. | DOI: 10.4103/0973-0354.116129.
(4) Thyroid Research and Practice. Medknow Journal (2013).
(5) Godkar PB, Godkar DP. Text book of Medical laboratory technology (4th edition, 2024), Bhlani Publishers, Mumbai. India.
(6) Wangi Thorn. Economic Burden of Thyroid Disorders: A Comprehensive Health Economics Analysis. Opinion Article (2024), Volume 13, Issue 3.
(7) Ye-Xin Chen, Han-Zhang Hong 1, Zi-Heng Gao, Yu-Xin Hu, Ling-Zi Yao, Jiang-Teng Liu, Yan Zhao, Gai-Weng Cui, Dan-Dan Mao, Jin-Xi Zhao. Global trend and disparity in the burden of thyroid cancer attributable to high body-mass index from 1990 to 2021 and projection to 2049: a systematic analysis based on the Global Burden of Disease Study 2021.
(8) Hakan Cinemre, Cemil Bilir, Feyzi Gokosmanoglu, Talat Bahcebasi. Hematologic effects of levothyroxine in iron-deficient subclinical hypothyroid patients: a randomized, double-blind, controlled study. Randomized Controlled Trial J Clin Endocrinol Metab ( 2009), Jan;94(1):151-6. doi: 10.1210/jc.2008-1440.
(9) Status of Goitre or Thyroid Disorders in India. National Family Health Survey IV [NFHS IV (2015-2016)] and NFHS-V (2019-2021). Posted On: 08 FEB 2022 12:38PM by PIB Delhi.
