1. Dr Andrew S Bates Heart of England Foundation Trust
Thyroid Disease
Dr Andrew S Bates
Heart of England Foundation Trust

2. Outline What and where is it? What does it do? How is it controlled?
What can go wrong with it?
Functional disorders
Hyper- and Hypothyroidism
Goitre, nodules and tumours

3. The normal thyroid

4. What does the thyroid do?
Secretes thyroid hormones (T4 and T3)
Control basal metabolic rate
Burn fat
Increase heart rate
Increase bone turnover

5. Thyroid Physiology Heavily dependent on iodine
Iodination of thyroglobulin resulting in formation of mono- and di-iodotyrosines
Iodotyrosines combine to form T4 (100%) and T3 (20%) - released into circulation
80% of T3 is formed outside the thyroid
Deiodinases play important role in thyroid metabolism

6. How is it controlled?

7. What do we measure? TSH-most important FT4 and FT3 Thyroid antibodies
Low or ‘turned off’ if overactive
High if underactive
FT4 and FT3
Occasionally useful in addition to TSH
Thyroid antibodies
Non-diagnostic but useful as a pointer to autoimmune thyroid disease

8. What can go wrong? Overactive Underactive Thyroid growths
High free T4 low or suppressed TSH
Underactive
Low free T4 and high TSH
Thyroid growths
Goitre, nodules, cancer

9. Overactive thyroid

10. Thyroid Hormone Excess Clinical Features
General
Heat intolerance, fatigue, tremor.
Cardiovascular
Tachycardia, heart failure.
Gastrointestinal
Weight loss, diarrhoea
Ophthalmological
Lid lag, ophthalmopathy

11. Thyroid Hormone Excess Clinical Features
Genitourinary
Amenorrhea, infertility.
Neuromuscular
Proximal muscle weakness, HPP, MG
Psychiatric
Irritability, agitation, anxiety, psychosis
Dermatological
Pruritus, hair thinning, onycholysis, vitiligo.

12. Causes of Thyroid Hormone Excess
Increased iodine uptake
Graves
Toxic Multinodular Goitre
Toxic solitary adenoma

13. Causes of Thyroid Hormone Excess
Reduced iodine uptake
Thyroiditis
Iodine induced (Amiodarone)
Factitious

14. Increased iodine uptake

15. Selective iodine uptake

16. No iodine uptake

17. Graves Disease Most common cause in UK Diffuse Goitre Hyperthyroidism
Ophthalmopathy
Dermopathy
Autoimmune.

18. Toxic Multinodular Goitre
Older
Usually less severe hyperthyroidism
May have subclinical hyperthyroidism(normal thyroid hormones, low TSH)
May have long history of goitre

19. Toxic Solitary Adenoma
Rare cause (< 2% of patients with hyperthyroidism)
Younger people 30’s and 40’s
Isotope scan useful
Benign follicular adenomas

20. Thyroiditis Painful (subacute, de Quervain’s) Painless (post partum)
Hyperthyroid, hypothyroid and euthyroid phases
Anti thyroid drug therapy does not work

21. Treatment of hyperthyroidism
Antithyroid drugs
Carbimazole 10 mg tid
Reduce to maintenance after 4 weeks
Rash, GI, agranulocytosis
Graves – withdraw drugs after course of treatment

22. Treatment of hyperthyroidism
Radio-iodine
Inflammatory response followed by fibrosis
May be used for Graves, TMG or TA
? Need for drug treatment before and after
May need retreatment
Long term risk of hypothyroidism

23. Treatment of Hyperthyroidism
Surgery
Rarely used nowadays
Need to be rendered euthyroid before surgery
Lugol’s iodine mls tid for 10 days before surgery

24. Graves Eye Disease Onset relative to hyperthyroidism is variable.
Pain, watering, photophobia, blurred vision, double vision
Usually mild – Tx, protective glasses, elevate head of bed, conjunctival lubricants

25. Graves Eye Disease High dose steroids External radiotherapy
Orbital decompression

26. Thyroid Eye Disease

27. Hypothyroidism Autoimmune Hashimoto’s Iatrogenic Congenital
Hypopituitarism

28. Treatment Thyroxine – variable doses. Aim to normalize TSH
In patients with heart disease start with lower dose e.g. 25ug once daily.

29. Multinodular Goitre

30. Simple non-toxic goitre
Normal TFT’s
No treatment required
Surgery if obstructive symptoms

31. Nodular Thyroid Disease
Prevalence 5-50%
Depending on age and methods used
Clinically apparent nodules in 4-7% UK population
Four times more common in women
<5% are cancerous

32. Nodular Goitres Factors Favouring Benign Factors Favouring Benign Disease
Age
Family history of benign thyroid nodule
Presence of hyperthyroidism
Associated pain or tenderness
Soft, smooth, mobile nodule
Multinodular goitre without a dominant nodule

33. Nodular Goitres Factors Favouring Benign Management
Clinical history and examination
Thyroid function tests
Ultrasound
Fine Needle Aspiration
Surgery

34. Conclusion A small but very important gland with many vital functions
Commonly develops faults, but fortunately most are easily sorted out