Hyperthyroidism, Hypothyroidism/Thyroiditis 1

Question 1

What are the primary causes of hypo and hyperthyroidism in general ?

Answer 1

Thyroid disease

Question 2

What are the secondary causes of hypo and hyperthyroidism in general ?

Answer 2

• Hypothalmic disorders
• Pituitary disorders

Question 3

When measuring thyroid hormone levels what is measured?

Answer 3

• TSH
• Free T3/T4

Question 4

Describe the results for lab diagnosis of primary, secondary and sub-clinical hypothyroidism

Answer 4

• Primary - TSH High, T4/T3 low
• Sub-clinical - TSH high, T3/T4 normal
• Secondary - TSH low, T3/T4 low

Question 5

What is myxoedema?

Answer 5

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

Question 6

What is myxoedema most commonly associated with ?

Answer 6

Hypothyroidism

Question 7

What type of myxoedema is associated with hyperthyroidism ?

Answer 7

Pretibial myxoedema

Question 8

What are the primary causes of hypothyroidism?

Answer 8

Goitres:

• Hashimotos thyroiditis (most common)
• Iodine deficiency (non-toxic multi-nodular goitre)

Non-goitrous:

• Congenital developmental defect
• Atrophic thyroiditis
• Post-ablative (radio/surgery)
• Self-limiting (following withdrawal of suppressive therapy)

Question 9

How does Hashimotos thyroiditis cause hypothyroidism and what is it characterised by ?

Answer 9

Causes autoimmune destruction of thyroid gland ==> reduced thyroid hormone production

Characterised by:

• Presence of thyroid peroxidase antibodies. (TPO)
• T-cell infiltration and inflammation on microscopy

Question 10

Describe the progression of hypothyroidism in terms of the thyroid hormones

Answer 10

Question 11

What are the symptoms of hypothyroidism ?

Answer 11

• Fatigue/muscle weakness
• Increased sensitivity to cold
• Constipation
• Dry skin
• Unexpected weight gain
• Puffy face
• Hoarseness
• 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

Question 12

What are the further lab results of someone with hypothyroidism ?

Answer 12

• TSH high
• T4/T3 low
• Elevated creatinine (CK)
• Increased LDL
• Hyperprolactinaemia

Question 13

Go over the thyroid antibodies

Answer 13

Question 14

What is the treatment of hypothyroidism ?

Answer 14

Thyroxine (T4) - levothyroxine

Note - normal metabolic rate should be restored slowly as it can precipitate arrhythmias

Question 15

What is myxoedema coma ?

Answer 15

It is loss of brain function as a result of severe longstanding hypothyroidism

Question 16

What are the symptoms of myxoedema coma ?

Answer 16

• Body temp may be as low as 26.6
• Severe mental changes including hallucinations, disorientation, seizures, and ultimately deep coma

Question 17

What is the treatment of myxoedema coma ?

Answer 17

• Give T3 as faster acting - liothyronine
• Give hydrocortisone
• Rehydrate
• If caused by infection then antibiotics
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Question 18

Who does myxoedema typically affect?

Answer 18

Elderly women with long standing but frequently unrecognised or untreated hypothyroidism