THYROID Function tests

Question 1

T3 and T4 increase/decrease catecholamine effects.

Answer 1

Increase

Question 2

When is TBG increased (3)

thyroxine-binding globulin

Answer 2

Pregnancy
Hepatitis
E2 therapy (pill/HRT)

Question 3

When is TBG decreased (2)

Answer 3

Nephrotic syndrome
Malnutrition
Acromegaly
Chronic liver disease

Question 4

Why dont you ask for T3 in hypothyroidism

Answer 4

T3 adds no extra infomation. (Ask for T4 and TSH)

Question 5

How does sick euthyroid present on testing

Answer 5

Supressed TSH/T3/T4 (repeat test after recovery)

Question 6

High TSH, High T4, low T3 indicates what

Answer 6

Slow peripheral conversion of T4–>T3 (deiodinase deficiency/euthyroid hyperthyroxinaemia).

Question 7

Cystic and solid nodules indicate what

Answer 7

Benign and malignant respectively

Question 8

20% of hot/cold nodules are malignant

Answer 8

cold

Question 9

Surgery indicated on nodules if

Answer 9

Rapid growth
>3cm
Compression signs
It is the dominant nodule on scintography
Hypo-echogenicity

Question 10

Who gets thyroid function screening

Answer 10

Atrial fibrillation patients
Hyperlipidaemic patients
DM
Pregnant women with DM1 (once during 1st trimester and again post-delivery)
Amiodarone/lithium 
Downs/turners syndrome

Question 11

What is the spot on an isotope scan below the thyroid

Answer 11

Sternal marker

Question 12

Why is free t3/t4 more useful than total

Answer 12

Total affected by TBG