12.8 Thyroid Dysfunction Flashcards
Hypothyroidism
Def
Causes
Subclinical
Def
- lack of thyroid hormones
- ⬇️ basal metabolic rate
- T3/4 inadequate
- ⬆️ TSH
Causes
Primary - thyroid gland not making enough TH
- caused by disease of thyroid
- autoimmune / atrophic hypothyroidism (anti-thyroid antibodies)
- Hashimoto’s (goitre formation; TPO antibodies)
- De Quervain’s
- inflammatory processes of tissues of thyroid gland
Secondary - stimulated fibroblasts in skin and soft tissues
Subclinical
- ⬆️ TSH
- Normal fT4 levels
- treated in preg + <70 (especially with cardiac risk)
Before subclinical: overt hypothyroidism (⬇️T3/T4)
Hypothyroidism
Complications
- reduced hearing
- goitre
- pleural effusion
- shortness of breath
- weight gain
- constipation
- muscle cramps
- fatigue + tiredness
- cognitive dysfunction
- slow speech
- depression
- bradycardia
- pericardial effusion
- reduced left ventricular func
- diastolic hypertension
- irregular ± heavy periods
- loss of libido
- subfertility
- paraesthesia
- brittle nails
Hyperthyroidism
Def
Commonest causes
Differentiating between causes
Subclinical
Def
- overactive thyroid
- TSH-like molecules stim thyroid (TSH receptor antibodies; HCG in large quantities)
- ⬆️ level of TH in blood
- ⬆️ T4/3
- ⬇️ TSH
- “speed things up”
Causes
- Autoimmune thyroid disease (Graves’ disease: TSH receptor antibodies)
- Autonomous thyroid tissues
➡️Toxic adenoma
➡️Toxic multinodular goiter
- Subacute thyroiditis
➡️Subacute granulomatous thyroiditis (paintu
➡️Subacute silent thyroiditis (painless) ;Includes postpartum thyroiditis
- Exogenous thyroid hormone intake
➡️Excessive replacement dose
Differentiating
- diffuse goiter - graves
- exophthalmos - graves
- pain & tenderness on thyroid - subacute thyroiditis
- nodular goiter - toxic adenoma / toxic nodular goiter
Subclinical
- ⬇️ TSH
- normal T3/4
- RF: risk for bone & cardiac complications
Complications of thyrotoxicosis (hyperthyroidism)
- emotional lability
- insomnia
- mood disturbance
- poor concentration
- restlessness
- tremor
- myopathy
- increased bone turnover
- osteoporosis
- pulmonary hypertension
- tachycardia
- A fib
- ⬆️ cardiac Output
- ⬆️ motility
Entity of thyroiditis (types)
Thyroiditis
- hashimoto’s
- painless postpartum
- painless sporadic
- painful subacute
- suppurative
- drug-induced (amiodarone, lithium, interferon alfa)
- riedel’s thyroiditis
Thyroid strom
Extreme hyperthyroidism
Decompensated thyrotoxicosis
- very high T3/4
- undetected TSH
When it turns to thyroid storm:
- undiagnosed
- untreated
- non compliant
- stress
Myezedema coma
Decompensated hypothyroidism
- organs failing
- delirium
- hypothermia
- bradycardia, shock
- hypoglycaemia
EMERGENCY
Physiological stress turns com -> decompensated (sepsis, cold exposure, surgery, burns, trauma)
Grave’s disease
General
Clinical diagnosis
- TSH-like: TSH receptor
- ± enlarged thyroid
- bruit
- bulging eyes
- goiter
- young women
Clinical diagnosis
- Diffuse enlargement of thyroid
- Ophthalmopathy
- Thyroid dermopathy (pretibial myxaodema)
- Bruit
