Thyroid Disorders: Hyperthyroidism

Question 1

Define ‘hyperthyroidism’

Answer 1

When the thyroid gland is overactive and produces excessive thyroid hormone

Question 2

What are the main 3 points for epidemiology of hyperthyroidism

Answer 2

1. ) More females affected than males
2. ) Affects 2-5% of women
3. ) Presents at ages 20-40

Question 3

State the main risk factors for developing hyperthyroidism (5)

Answer 3

1. ) Female
2. ) Family history (associations w/ HLA-B8/DR3/DR4)
3. ) Stress
4. ) Smoking
5. ) Amiodarone (an antiarrhythmic drug)

Question 4

Causes (6)

Answer 4

1. ) Graves disease: autoimmune condition that causes an excessive production of thyroid hormone
2. ) Toxic multinodular goitre: are swellings on the thyroid
3. ) Toxic thyroid adenoma: a singular goitre on the thyroid. Responsible for 5% of cases
4. ) Pituitary adenoma: causes more TSH production results more T3/T4 production
5. ) De Quervain’s thyroiditis: accompanied by fever/malaise/neck pain
6. ) Drug induced: by iodine, amiodarone and lithium

Question 5

Pathophysiology: Graves Specifically

Answer 5

• In Graves you have IgG antibodies called: TSH receptor stimulating antibodies (TRAb)
• These bind to TSH receptors on the thyroid + stimulate T3/4 production

Question 6

Signs (something you would see from an examination or investigation)

Answer 6

1. ) Tackycardia (Most important one!!!)
2. ) Goitre
3. ) Tremor
4. ) Hyperkinesia
5. ) Thin hair
6. ) Onycholysis (nail separates from nail bed)
7. ) Exophthalmos

Question 7

Symptoms: Graves only

Answer 7

1.) Graves ophthalmology: protruding eye/eye discomfort/lacrimation/diplopia

Question 8

Symptoms for hyperthyroidism: general

Answer 8

1. ) Weight loss
2. ) Irritability
3. ) Heat intolerance
   - These 3 are the KEY ones
4. ) Insomnia
5. ) Diarrhoea/sweats/palpitations

Question 9

Investigations and results you would see

Answer 9

1. ) Thyroid function tests:
   - Primary: low TSH with high T3/T4
   - Secondary: high TSH with high T3/T4
2. ) Thyroid antibodies:
   - Thyroid peroxidase antibodies
   - Thyroglobulin antibodies
   - TSH receptor antibody (GRAVES ONLY)
3. ) Thyroid ultrasound
4. ) Radioactive iodine isotope uptake scan

Question 10

Define and explain the main treatment options for hyperthyroidism

Answer 10

1. ) Carbimazole: blocks thyroid hormone synthesis. Has two strategies called ‘titration’ and ‘black and replace’. Aim is to keep free T4 and TSH levels normal. Severe side effect is agranulocytosis
2. ) Beta blockers: doesn’t directly stop thyroid hormone production but will decreases SNS activation
3. ) Radioiodine therapy: iodine taken up and tissue damage will cause normal function. BUT could lead to hypothyroidism
4. ) Thyroidectomy: the removal of the thyroid gland. Can lead to complications including bleeding/hypothyroidism/recurrent laryngeal palsy

Question 11

Complications of hyperthyroidism

Answer 11

1. ) Congestive heart failure
2. ) Atrial fibrillation (from tachycardia)
3. ) Osteoporosis
4. ) Graves ophthalmopathy complications
5. ) Graves dermopathy: elephantitis

Question 12

Explain the most severe and acute complication of hyperthyroidism

Answer 12

• Thyroid Crisis (aka a thyroid storm)
• A rare condition where there is a rapid deterioration of thyrotoxicosis with hyperpyrexia and tachycardia
• Precipitated by infection/stress surgery
  Treatment/ big doses of carbimazole/propranolol/potassium iodide/hydrocortisone