1. Clinical presentation of thyroid disease

Question 1

Definition of Goitre

Answer 1

Enlargement of thyroid gland

- May be diffuse or localized

Question 2

Types of functional derangement in thyroid disease

Answer 2

1. Hyperthyroidism

2. Hypothyroidism

Question 3

Hyperthyroidism

Answer 3

1. Hyperfunctioning of the thyroid gland
2. Most common cause of thyrotoxicosis (hypermetabolic state caused by increased circulating levels of free T3 & T4)
3. Results in thyrotoxicosis:
   - Increased basal metabolic rate
   - Increased catabolism (of muscle, bone etc)
   - Increased beta adrenergic stimulation
   - Increased excitability of neurons

Question 4

Hypothyroidism

Answer 4

1. Hypofunctioning of the thyroid gland
2. If in adulthood, results in myxedema:
   - Decreased basal metabolic rate
   - Decreased catabolism (of matrix substances, etc)
   - Decreased beta adrenergic stimulation
   - Decreased excitability of neurons
3. If in infancy or childhood, results in cretinism:
   - Impaired skeletal growth (short stature)
   - Impaired CNS growth (mental retardation)
   - Others (coarse facial features, protruding tongue, umbilical hernia)

Question 5

Clinical features in hyperthyroidism

Answer 5

1. Weight loss
2. Heat intolerant
3. Oligomenorrhea
4. Diarrhoea
5. Irritable
6. Increased appetite
7. Staring gaze, lid lag (due to excessive sympathetic stimulation of the levator palpebrae superioris), exophthalmos***
8. Warm, sweaty, flushed skin
9. Tachycardia, atrial fibrillation (due to increased beta adrenergic stimulation)
10. Proximal myopathy (due to increased muscle catabolism), pretibial myxedema
11. Increased bone resorption (increases porosity of cortical bone, decreases volume of trabecular bone)

***only seen in Graves Disease

Question 6

Clinical features in hypothyroidism

Answer 6

1. Weight gain
2. Cold intolerant
3. Oligomenorrhea or menorrhagia
4. Constipation
5. Mental slowness, general fatigue & apathy
6. May have decreased appetite
7. Peaches & cream skin, broadening & coarsening of facial features (due to decreased catabolism of matrix substances)
8. Cool, dry, pale skin
9. Bradycardia, pericardial effusion, with decreased cardiac output leading to decreased exercise capacity
10. Proximal myopathy (due to decreased metabolism)
11. Increased total cholesterol & LDL (atherogenic profile)
12. Increased matrix substance accumulation in skin & some visceral sites, causing hoarsening of voice, enlargement of tongue, non-pitting edema etc