Thyroid

Question 1

What is the most common type of hypothyroidism

Answer 1

Hypothyroidism is a thyroid hormone deficiency. The thyroid is essential for normal growth, development and metabolism.

• most common type is primary hypothyroidism (95%)

Question 2

What is primary hypothyroidism?

Answer 2

Occurs when the thyroid gland is unable to produce thyroid hormones due to an iodine deficiency or abnormality with the thyroid gland

Question 3

How would you manage a pregnant woman with thyroid problems?

Answer 3

Refer to endocrine asap

Question 4

What is overt Hypothyroidism?

Answer 4

TSH level above the normal reference (above 10 mU/L) and free thyroxine (FT4) below the normal range

Question 5

What is subclinical hypothyroidism?

Answer 5

Where TSH levels are above normal range but T3+T4 are within range

Question 6

What is secondary hypothyroidism ?

Answer 6

Hypothyroidism resultant of insufficient thyroid stimulation due to pituitary or hypothalamic disorder.

Question 7

What are the causes of primary hypothyroidism?

Answer 7

1. Iodine deficiency (diet - most common cause)
2. Autoimmune thyroiditis (most common cause in iodine sufficient areas)
3. Post- ablative therapy or surgery
4. Drugs (Lithium, amiodarone, rifampicin (TB drug)
5. Postpartum thyroiditis (PPT)

Question 8

What causes secondary hypothyroidism?

Answer 8

1. Tumour (Pituitary adenomas or gliomas
2. Surgery
3. Pituitary infarction
4. Sheehan’s syndrome (postpartum pituitary necrosis due to postpartum haemorrhage)
5. Drugs (cocaine, dopamine, steroids + metformin)

Question 9

Complications of not being treated for hypothyroidism?

Answer 9

1. Dyslipidaemia
2. Metabolic syndrome
3. Coronary heart disease + stroke
4. Heart failure
5. Increased risk of infertility
6. Neurological and cognitive sx. such as decreased taste, vision or hearing
7. Myxoedema coma (medical emergency: lethargy, bradycardia, hypothermia, seizures and/ or coma)

Question 10

Symptoms of primary hypothyroidism

Answer 10

1. Fatigue / lethargy, cold intolerance, weight gain, constipation
2. Non specific weakness, arthralgia + myalgia
3. Menstrual irregularities, infertility or subfertility
4. Depression, impaired concentration and memory
5. Dry skin and hair loss (lateral eyebrows)
6. Thyroid pain
7. Coarse dry hair and skin + hair loss
8. Cardio: Bradycardia + diastolic HTN, pericardial effusion
9. Paraesthesia or peripheral neuropathy

Question 11

Symptoms of secondary hypothyroidism

Answer 11

• clinical features of primary hypothyroidism along with sx of pituitary disease such as recurrent headaches, diplopia and /or visual field defects

Question 12

Symptoms of subclinical hypothyroidism + how do you manage this

Answer 12

Clinical features are usually absent but if present are related to the degree of TSH elevation

Mx:
Repeat in 3 months. Diagnosis can be made if the TSH level is elevated twice, at ;east three months apart