Hyperthyroidism Flashcards
What are the common causes of hyperthyroidism?
- Graves Disease
- Toxic nodular goitre
What is the cause of Graves disease?
Antibodies formed within thyroid that bind to TSH receptors on follicular cells and stimulate thyroid hormone synthesis and secretion.
What are the uncommon causes of hyperthyroidism?
- Subacute thyroiditis
- Amiodarone therapy
- Hashimoto’s thyroiditis
- Iodine-induced
TSH- secreting pituitary tumour = v rare
What is the clinical presentation of hyperthyroidism?
- Neuromuscular: Weakness, nervousness, shakiness, anxiety, irritability
- Eyes: Sore and gritty, thyroid-associated opthalmopathy
- Cardiopulmonary: Breathlessness, palpitations
- GI: Diarrhoea, weight loss, polyphagia
- General: Weight loss, tiredness, heat intolerance, sweating
What signs are seen in hyperthyroidism?
- Proximal myopathy
- Tremor
- Restlessness
- Anxiety/psychosis
- Eyes: Staring eyes, lid lag, thyroid-associated opthalmopathy
- Goitre
- Tachycardia
- AF
- Warm, sweaty palms
- Palmar erythema
- Skin = pretibial myxoedema (only in GD)
What are the features of thyroid-associated opthalmopathy that can be found in any hyperthyroid patient?
- Sore, gritty eyes
- Lid retraction
- Staring eyes
- Lid lag
What features of thyroid-associated opthalmopathy are exclusive to Grave’s disease?
- Watery eyes
- Retro-orbital pain
- Photophobia
- Conjunctival and peri-orbital oedema
- Double vision
- Corneal ulceration
- Proptosis
- Decreased visual acuity (URGENT)
What investigations are done in hyperthroidism?
Free T4 and T3
Measure TSH
Solitary toxic nodule can be diagnosed with isotope scan in pt with hyperthroid and clinically obvious solitary nodule.
What extra-information is gained from measuring TSH?
- Thyroid autonomy leads to feedback suppression of TSH therefore TSH is decreased.
- TSH may be decreased before T3/T4 raised therefore v sensitive test.
- Will detect v rare cases where thyrotoxicosis due to increased pituitary TSH secretion.
What is the first line management of hyperthyroidism?
- Antithyroid drugs: Carbimazole/propylthiouracil (thyroperoxidase inhibitors)
What are the side effects of these drugs for hyperthyroidism?
- Most common = rash (others = jaundice, nausea)
- Most dangerous = agranulocytosis
What other therapy can be used in hyperthyroidism? When can it not be used?
Radioiodine
Absolutely contraindicated in children, nursing mothers or women who may get pregnant due to risk of thyroid cancer, transmission in breast milk and congenital malformations resp.
When is surgery indicated in hyperthyroidism?
- Those who have particularly large goitres
- Those who respond poorly to other forms of treatmen
