Hypothyroidism Flashcards
Hypothyroidism is a common endocrine disorder characterised by decreased thyroid hormone production. What age does the incidence typically peak?
1 - 20-30
2 - 40-50
3 - 50-70
4 - 60-70
4 - 60-70
Incidence of 225.00 cases per 100,000
Is hypothyroidism more common in men or women?
- women
5:1 ratio
Although there are a variety of causes of hypothyroidism, what is the most common cause in the developed world?
1 - Hashimoto’s thyroiditis
2 - Subacute thyroiditis (de Quervain’s)
3 - Riedel thyroiditis
4 - Post-thyroidectomy
5 - Radioiodine treatment
6 - Drug therapy (e.g. lithium, amiodarone or anti-thyroid drugs such as carbimazole)
7 - Dietary iodine deficiency
1 - Hashimoto’s thyroiditis
Although there are a variety of causes of hypothyroidism, what is the most common cause in the under-developed world?
1 - Hashimoto’s thyroiditis
2 - Subacute thyroiditis (de Quervain’s)
3 - Riedel thyroiditis
4 - Post-thyroidectomy
5 - Radioiodine treatment
6 - Drug therapy (e.g. lithium, amiodarone or anti-thyroid drugs such as carbimazole)
7 - Dietary iodine deficiency
7 - Dietary iodine deficiency
Typically because they do not fortify their foods with iodine
If the cause of hypothyroidism is associated with the pituitary gland, called hypopituitarism, would it just be low levels of thyroid that are present?
- No
Likely to be other hormones as well including low TSH and ACTH
One rare cause of hypothyroidism is Shehans syndrome. What is the cause of this?
1 - vasculitis
2 - major haemorrhage following birth
3 - autoimmunity
4 - trauma
2 - major haemorrhage following birth
Leads to Ischemia of the thyroid gland
Which of the following drugs is NOT associated with causing hypothyroidism?
1 - lithium
2 - amiodarone
3 - carbimazole
4 - levothyroxine
4 - levothyroxine
Give to people with hypothyroidism
Hashimoto thyroiditis is the most common cause of hypothyroidism and is an autoimmune condition. Which 2 of the following are commonly associated with this?
1 - anti-thyroid peroxidase (anti-TPO) antibodies
2 - antinuclear antibodies (ANA)
3 - anti-thyroglobulin (anti-Tg) antibodies
4 - thyroid stimulating auto-antibodies (anti-TSH)
1 - anti-thyroid peroxidase (anti-TPO) antibodies
3 - anti-thyroglobulin (anti-Tg) antibodies
Thyroglobulin present in follicular cells is converted in T3 and T4
Thyroid peroxidase catalyses oxidation of iodine ions to iodine atoms that can then be added to Thyroglobulin to form T3 and T4
Hashimoto thyroiditis is the most common cause of hypothyroidism and is an autoimmune condition. Does this initially cause a goitre or atrophy?
- goitre
Then atrophy as hypothyroidism sets in
Which of the following is NOT a common clinical feature of hypothyroidism?
1 - Weight loss
2 - Lethargy/fatigue
3 - Cold intolerance
4 - Dry (anhydrosis (no sweat), cold, yellowish skin
5 - Non-pitting oedema (e.g. hands, face)
6 Dry, coarse scalp hair, loss of of eyebrows
7 - Constipation
8 - Menorrhagia
9 - Decreased deep tendon reflexes
10 - Carpal tunnel syndrome
1 - Weight loss
Causes weight gain
In primary hypothyroidism the thyroid gland is the issue. Which of the following would we expect to see when testings TFTs in an attempt to diagnose patients?
1 - low TSH, T3 and T4
2 - high TSH, T3 and T4
3 - high TSH, low T3 and T4
4 - low TSH, high T3 and T4
3 - high TSH, low T3 and T4
No negative feedback, and pituitary gland over secretes TSH to try and get the thyroid gland working again
In secondary hypothyroidism the pituitary gland is the issue. Which of the following would we expect to see when testings TFTs in an attempt to diagnose patients?
1 - low TSH, T3 and T4
2 - high TSH, T3 and T4
3 - high TSH, low T3 and T4
4 - low TSH, high T3 and T4
1 - low TSH, T3 and T4
No production of TSH, so thyroid is not stimulated to secrete T3 and T4
What is the primary treatment for hypothyroidism?
1 - thyroidectomy
2 - iodine supplements
3 - iodine radio-ionisation
4 - levothyroxine
4 - levothyroxine
Synthetic T4 that can also be metabolised into T3
Levels are titrated until TSH levels are normal
Monthly, annually unless symptomatic
High TSH = lower dose of levothyroxine
Low TSH = higher dose of levothyroxine
