Hyperthyroidism is an autoimmune disorder. It has a global prevalance of 0.2%-1.3%. Also known as overactive thyroid. Hyperactivity of thyroid gland with sustained increase in synthesis and release of thyroid hormones. It makes the thyroid bigger than usual.

1. University of Chakwal, Pakistan

2. Topic: Hyperthyroidism
Department of Zoology
Presented by: Hira Tariq
Roll no UOC-BSZOL-F2020/028
BS Zoology
Session:2020-2024
Subject: Endocrinology
Instructor Name: Dr Syeda Nadia Ahmad

3. ➢Introduction
➢Thyroid Gland
Hormones
➢Disturbances
➢Thyrotoxicosis
➢Symptoms
➢Causes
➢Effects
➢Complications
➢Treatment
➢References

4. Introduction
Hyperthyroidism is an autoimmune disorder.
It has a global prevalance of 0.2%-1.3%.
Also known as overactive thyroid.
Hyperactivity of thyroid gland with sustained increase in
synthesis and release of thyroid hormones.
It makes the thyroid bigger than usual.
Thyroid gland is found in neck below the laryngeal prominence
Adam’s Apple (Berada, 2020).

5. Fig. 1: Hyperthyroidism
https://images.app.goo.gl/bXYc87ATqkEsoUtJ8

6. Fig. 2: Thyroid Gland Hormones
https://images.app.goo.gl/RAcJPReDXDP7HZga8

7. Fig. 3: Hypothalamic Pituitary Thyroidal Axis
https://images.app.goo.gl/NDNBDm5hNoJUJdDf9

8. Disturbances in Thyroid Hormones
 Disorders of the thyroid gland can result in excess T3 and T4 production
along with compensatory decrease of TSH.
 These disturbances can be caused by synthetic chemicals and bioactive
compounds from food that interfere with any aspect of the hypothalamus–
pituitary–thyroid axis, thyroid hormone biosynthesis and secretion, blood
and transmembrane transport, metabolism and local actions of thyroid
hormones.
 These can affect heart rate, mood, energy level, metabolism, bone health,
pregnancy and many other functions.

9. Disturbances in Thyroid Hormones
A high calcitonin level means that the C cells in thyroid
are making too much calcitonin.
The higher the level, the more it is to have meduallary
thyroid cancer or C-cell hyperplasia.

10. Thyrotoxicosis
It is a hypermetabolic condition.
Results from the circulating levels of Thyroxine and triiodothyronine.
Occurs in women more than men (Guerri, 2019).
Symptoms
Losing weight.
Taachycardia and arrhythmia.
Heart Palpitations.

11. Symptoms
Increased hunger, sleep problems and anxiety.
Tremor and sweating.
Muscle weakness.
Bulging eyes.
Goiter.
Menstrual cycle changes (Bartalena, 2022).

12. Causes
Grave’s Disease
Results in the overproduction of thyroid hormones.
Excess Iodine
Iodine is a key ingredient of thyroid hormones thyronine and
triiodothyronine.
Benign Thyroid Nodules
Produces excess thyroid hormones.

13. Causes
Toxic Thyroid Nodules
 Some thyroid nodules are malignant and are determined by
ultrasound.
T4 in Blood
It results from taking certain dietary supplements or too much of
the thyroid hormone medication, levothyroxine (Berada, 2022).

14. Effects
 Hyperthyroidism causes TSH levels to drop below the expected levels. This happens
because the pituitary gland senses the increase in thyroid hormone levels in the blood and
respondsby reducingTSH production.
 Hyperthyroidismhas various effects on the body’s physiological system including:
1. CardiovascularSystem
 Increased Heart Rate (Tachycardia): Thyroid hormones stimulate the heart, leading to an
increased heart rate. This can result in palpitations and, in severe cases, may contribute to
the development of arrhythmias.
2. GastrointestinalSystem
 Increased Appetite: Hyperthyroidism can lead to an increased appetite, contributing to
weight loss (Coperchiniet al., 2021).

15. Effects
3. Metabolic System
 Increased Metabolism: Thyroid hormones play a crucial role in regulating metabolism. In
hyperthyroidism, there is an accelerated breakdown of nutrients and increased energy
production, leading to weight loss despite increased appetite.
 Increased Heat Production: Metabolism generates heat, and the excess thyroid hormones
can contribute to heat intolerance and increased sweating.
4. Endocrine System
 Menstrual Irregularities: Hyperthyroidism can affect the menstrual cycle, leading to
irregular periods or, in some cases, amenorrhea.
5. Integumentary System (Skin, Hair, and Nails)
 Thinning Hair: Hair loss and thinningare common in hyperthyroidism.
 BrittleNails: The condition may contributeto brittlenails (Coperchiniet al., 2021).

16. Effects
6. NervousSystem
 Nervousness and Anxiety: Excess thyroid hormones can affect the central nervous
system, leading to symptoms such as nervousness, anxiety, and irritability.
 Tremors: Fine tremors, particularly in the hands, may be present in individuals with
hyperthyroidism.
7. ReproductiveSystem
 Fertility Issues: Hyperthyroidism can impact fertility, and women may experience
difficulties in conceiving.
8. Ophthalmic System (in Graves' Disease)
 Graves' Ophthalmopathy: In Graves' disease, an autoimmune condition associated
with hyperthyroidism, individuals may experience eye problems such as bulging eyes
(exophthalmos), doublevision, and eye irritation (Coperchini et al., 2021).

17. Complications
Hyperthyroidism leads to many complications.
Thyroid Storm
It is a health condition as a result of untreated
hyperthyroidism. It has life threatening symptoms.

18. Complications in pregnancy
People with existing thyroid disorder or develop during
pregnancy has harmful effects on both mother and fetus. It leads
to miscarriage or immature birth.
Osteoporosis
It causes osteoporosis. One should take vitamin D and calcium
supplements.

19. Complications
Cancer
Hyperthyroidism develop thyroid cancer called thyroid
carcinoma.
Stroke
 Hyperthyroidism can cause atrial fibrillation which leads to
stroke or heart failure (Li Volsi & Baloch, 2018).

20. Diagnosis
Doctors usually diagnose hyperthyroidism based on symptoms.
T4 and T3 Level Test
This test is conducted to find the levels of T4 and T3 in blood.
CT Scan or MRI
It shows the presence of pituitary tumor.

21. Diagnosis
TSH level Test
 It is a pituitary gland hormone that stimulates the thyroid to produce
hormones.
Low TSH is an early sign of hyperthyroidism.
Thyroid Scan
Images of thyroid is taken and it will detect that either the whole gland
is damaged or any area (Wiersinga et al., 2023).

22. Treatment
The treatment could be done by:
Medication
Antithyroid medication drugs are:
1. Methimazole (MMI)
2. Propylthiouracil (PTU)
These drugs may cause side effects such as joint pain, hair loss and
rashes.

23. Treatment
Radioactive Iodine
 It is usually taken as oral tablet or in liquid form.
RAI is used in higher doses to treat thyroid cancer. It destroy the
cancer cells.
High doses of RAI in men may impact fertility. (Lee & Pearce,
2023).

24. Anti thyroid therapy
It is the simplest way to treat hyperthyroidism. Drugs are used for
treatment. Methimazole is used in most conditions. In pregnancy
propylthiouracil is used.
Surgery
Surgery is done in those cases when the patient is not able to
respond to any other kind of medication or treatment options.

25. Thyroid Gland Removal
This is the ultimate solution to treat severe condition of
hyperthyroidism as like thyroid cancer. The thyroid gland is
removed. After thyroid gland removal, patient needs to take
supplements of T4 and T3 throughout life.
Surgery is done by an endocrine surgeon (Guerri et al., 2019).

26. Fig. 4: Thyroid Gland Removal
https://images.app.goo.gl/u52r2qAj6dC2CQqB8

27. References
 Bartalena, L., Piantanida, E., Gallo, D., Ippolito, S., & Tanda, M. L. (2022). Management of Graves’
hyperthyroidism: Present and future. Expert Review of Endocrinology & Metabolism,17(2), 153- 166.
 Bereda, G. (2022). Hyperthyroidism: Definition, Causes, Pathophysiology and Management. Journal of
Biomedical and Biological Sciences, 1(2), 1-11.
 Coperchini, F., Croce, L., Ricci, G., Magri, F., Rotondi, M., Imbriani, M., & Chiovato, L. (2021). Thyroid
disrupting effects of old and new generation PFAS. Frontiers in Endocrinology,11, 612320.
 Guerri, G., Bressan, S., Sartori, M., Costantini, A., Benedetti, S., Agostini, F., ... & Bertelli, M. (2019).
 Lee, S. Y., & Pearce, E. N. (2023). Hyperthyroidism: A Review. JAMA, 330(15), 1472-1483 LiVolsi, V. A., &
Baloch, Z. W. (2018). The pathology of hyperthyroidism.Frontiers in Endocrinology, 9, 737.
 Wiersinga, W. M., Poppe, K. G., & Effraimidis, G. (2023). Hyperthyroidism: aetiology, pathogenesis, diagnosis,
management, complications, and prognosis. The Lancet Diabetes & Endocrinology, 11(4), 282-298.