Thyroid Investigations Flashcards
What are the optimal ratios of;
FT3/FT4 =
T3/RT3 =
FT3/FT4 = >0.33 T3/RT3 = >6
What do comphressive thyroid tests NOT assess?
Tissue levels of T3
What is the opitmal range of TSH?
0.4-2.5
What is the optimal range of Total T4?
70-150
What is the opitmal range of FT4?
12.8-19.5pg/ml
What is the optimal range of FT3?
3.2-4.5pg/ml
What is the opitmal range of Thyroglobulin antibodies?
no optimal range
What is the optimal range of TPO antiobodies?
No optimal range
What is the optimal range of RT3?
11-18ng/dl
High TSH + Normal T4 and T3 =
subclinical hypothyroidism
High TSH + Low T4 + low/normal T3 =
Hypothyroidism
Low TSH + normal T4 and T3 =
Subclinical hyperthyroidism (unless on T4 therapy)
Low TSH + high/normal T4 and T3 =
Hyperthyroidism
Low TSH + low T4 and T3 =
Secondary hypothyroidism
What needs to be checked on a thyroid test for a full assessment?
Total and free T4, total and free T3, RT3 and thyroid antibodies
What is the most accurate way of measuring iodine status?
urine iodine test
What is the range of the ‘iodine goal’ in a urine test taken on the first urination of the day in children and adults?
100-199mcg/L
What is the range of the ‘iodine goal’ taken in a urine iodine test for pregnant women?
150-249mcg/L
On a urine iodine test, what level indicates iodine insufficiency in children and adults (unless pregnant)?
<100mcg/L
<20 = severely deficient
What test is a useful indicator for testing for low thyorid?
Barnes Basal Body Temperature Test
How does the Barnes Basal Body Temperature Test work?
auxillary temperature is taken on waking each monring for 7 days and an average is calculated. <36.5 indicated low thyroid
What can effect the Barnes Basal Body Temerptaure Test results?
Circadiuan changes Illness Menstrual changes Sedentary lifestyle Light exposure Alcohol intake
Name indicators of thyroid issues through physical examination
Presence of goitre dry skin nail beading thinning eyebrows hair loss low BP bradycardia (<60BPM)
Why is it useful to investigate SNPs when doing a thyroid report?
May cause; Thyroid imbalance AI Inflammation HPT axis Impact cofactors
Other than conventional testing a full thyroid panel, what other tests can be used for thyroid investigations?
Barnes Basal Body Temperature Test
Urine Iodine Test
Physical Examination
SNPs testing
