What are the primary causes of hypo and hyperthyroidism in general ?
What are the secondary causes of hypo and hyperthyroidism in general ?
- Hypothalmic disorders
- Pituitary disorders
When measuring thyroid hormone levels what is measured?
- Free T3/T4
Describe the results for lab diagnosis of primary, secondary and sub-clinical hypothyroidism
- Primary - TSH High, T4/T3 low
- Sub-clinical - TSH high, T3/T4 normal
- Secondary - TSH low, T3/T4 low
What is myxoedema?
It is swelling of the skin and underlying tissues due to accumulation of hydrophilic monosaccharides in the dermis and other tissues. Gives it a waxy consistency
What is myxoedema most commonly associated with ?
What type of myxoedema is associated with hyperthyroidism ?
What are the primary causes of hypothyroidism?
- Hashimotos thyroiditis (most common)
- Iodine deficiency
- Congenital developmental defect
- Atrophic thyroiditis
- Post-ablative (radio/surgery)
- Self-limiting (following withdrawal of suppressive therapy)
How does Hashimotos thyroiditis cause hypothyroidism and what is it characterised by ?
Causes autoimmune destruction of thyroid gland ==> reduced thyroid hormone production
- Presence of thyroid peroxidase antibodies. (TPO)
- T-cell infiltration and inflammation on microscopy
Describe the progression of hypothyroidism in terms of the thyroid hormones
What are the symptoms of hypothyroidism ?
- Fatigue/muscle weakness
- Increased sensitivity to cold
- Dry skin
- Unexpected weight gain
- Puffy face
- Elevated cholesterol
- Muscle aches and pains
- Pain, stiffness or swelling in your joints
- Heavier than normal or irregular menstrual periods
- Thinner hair
- Slower HR
- Depressed moods
- Impaired memory
What are the further lab results of someone with hypothyroidism ?
- TSH high
- T4/T3 low
- Elevated creatinine (CK)
- Increased LDL
Go over the thyroid antibodies
What is the treatment of hypothyroidism ?
Thyroxine (T4) - levothyroxine
Note - normal metabolic rate should be restored slowly as it can precipitate arrhythmias
What is myxoedema coma ?
It is loss of brain function as a result of severe longstanding hypothyroidism
What are the symptoms of myxoedema coma ?
- Body temp may be as low as 26.6
- Severe mental changes including hallucinations, disorientation, seizures, and ultimately deep coma
What is the treatment of myxoedema coma ?
- Give T3 as faster acting - liothyronine
- Give hydrocortisone
- If caused by infection then antibiotics
Who does myxoedema typically affect?
Elderly women with long standing but frequently unrecognised or untreated hypothyroidism