Thyroid Flashcards
(42 cards)
Symptoms of hypothyroidism
(Moms so tired) Memory loss Obesity Menorrhagia Slowness Skin and hair dry Onset is gradual Tiredness Intolerance to cold Raised BP Energy levels are low Depressed
Signs of hypothyroidism
(bRADYCARDIC) Reflexes relax slowly Ataxia Dry thin hair/skin Yawning Cold hands Ascites/non putting oedema Round puffy face Defeated demeanour Immobile C-CCF
Investigations of hypothyroidism
TFTs - free T4, TSH 1. Diagnose low T3,T4 2. Where is the problem? 1o - low T4, and High TSH 2o - low T4, and no compensatory increase in TSH
Treatment for hypothyroidism
Healthy and the young - levothyroixine(T4) 75-100mcg per day
Elderly and ischaemic heart disease - 25ug/day
How long does treatment for hypothyroidism take?
Clinical improvement within two weeks
Adjust dose every 4-6 weeks, T4 increases quickly TSH will take around six weeks
Pathogenesis of hashimotos thyroiditis
Autoimmune disease characterised by progressive destruction of the thyroid parenchyma “hurthle cell change” and mononuclear infiltrates without or with extensive fibrosis. It is mediated by multiple auto antibodies against thyroidperoxidase and TSH receptor
Clinical progression of hashimotos
Initial destruction of the thyroid gland can release the thyroglobulin colloid causing temporary hyperthyroidism(hashitoxocis) then euthyroid then hypothyroid
Painless enlargement of the thyroid
Amiodarone induced hypothyroidism
Used to treat heart conditions, this drug has a high iodine content. Inhibits the synthesis and release of the thyroid hormone and also conversion of t4 and t3
Other drugs that can cause hypothyroidism
Anti-thyroid medication, interferon-alpha and interleukin 2( malignancy), lithium (bipolar disorder)
Causes of hypothyroidism?
Autoimmune (hashimotos thyroiditis)
Primary(thyroidectomy, post radioactive iodine ablation, congenital biosynthesis defect, rare developmental abnormalities-thyroid dys genesis)
Secondary (pituitary, hypothalamic)
Antibodies in hypothyroidism
Anti-Tpo
Anti-Tg
Definition of hyperthyroidism
Over activity of the thyroid gland leading to excess thyroid hormone
Causes of hyperthyroidism
Graves disease Toxic multinodular goitre Toxic adenoma Ectopic thyroid tissue Exogenous
Symptoms of hyperthyroidism (sweating)
Sweating Weight loss Emotional lability Appetite increased Tremor/tachycardia due to af Intolerance to heat Nervousness Goitre and Gi upset(diarrhoea)
Signs of hyperthyroidism
Pulse is fast
Warm moist skin
Fine tremor
Lid lag(staring appearance)
TFTs for hyperthyroidism
- Diagnose high t3,t4
- Where is the problem ?
Decreased TSH suggests thyroid
Increased TSH suggests in or above pituitary
Other investigations for hyperthyroidism ?
Auto-antibodies for graves
ECG for AF
Radio-isotope scanning for “hot spots” –> toxic adenoma
Autoantibodies for graves disease
Thyrotropin receptor antibodies (TRABS)
Treatment for hyperthyroidism
B-blockers - rapid control of symptoms e.g anxiety and palpitations
Anti-thyroid medication
Partial thyroidectomy - thyroid gland is removed surgically leave some tissue plus parathyroid glands
Radioactive iodine - 131I is only absorbed by thyroid tissue, killing the cells and reducing thyroid hormone synthesis
Method of drug treatment in hyperthyroidism
- Block and replace - give carbimazole and thyroxine simultaneously less risk of iatrogenic hypo
- Titration - give carbimazole for 4 weeks reduce according to TFTs every 1-2 months
6months -31% remission
24 months -82%remission
Definition of graves disease
Autoimmune disease caused by circulating auto antibodies against TSH receptor so that thyroid hormones are produced in excess
Epidemiology of graves disease
Women 40-60years
Clinical features of graves disease
Thyrotoxicosis - classical signs of
Dysthyroid eye disease
Dermopathy - pretibial myxoedema (oedematous swelling above lateral malleolus)
Goitre- bruit as increased vasculature
Thyroid acropachy - clubbing, painful fingers
Graves Dysthyroid eye disease features
- exophthalmosis = bulging eyes
- upper lid retraction
- proptosis- eyes protruding from the orbit
- Diplopia- double vision
- nerve compression
- peri-orbital oedema