Thyroid Disorders Flashcards
Describe the etiology of goiter
Describe the presentation of goiter
Describe the diagnostics for goiter
Describe the treatment of goiter
What are the actions of T3 & T4
- increase basal metabolic rate & metabolism
- stimulate bone maturation & growth
- ensure proper fetal growth & development (esp CNS)
- increase cardiac output
What meds can suppress TSH
high dose steroids, dopamine
What meds can increase TSH
metoclopramide & amiodarone
Describe when to do thyroid screening
- newborn (screen for congenital hypothyroidism ( cretinism, intellectual disability))
- sometimes in pregnancy
- high index of suspicion in elderly pts
- if symptomatic
- when titrating certain meds (or when using amiodarone, Li, metoclopramide)
Describe the screening for thyroid conditions
TSH first (if normal, no further testing)
- if high: free T4, maybe T3 (if sus for hyperthyroidism)
- if low: free T4 & T3
Describe the difference between total vs free T3 & T4
Total: highly protein bound, many factors influence binding
Free: corresponds to biologically available hormone pool, unpound
Describe the consideration for biotin (Vit H, B7) in thyroid testing
- can impact TSH results
- stop at least 18 hrs prior to blood draw
Dx for high TSH & low Free T4
primary hypothyroidism (thyroid failure)
Dx if TSH is high but FT4 is normal
subclinical hypothyroidism
Dx if TSH is low & FT3/FT4 are high
primary hyperthyroidism (thyroid overproducing)
Dx if TSH is low and FT3/FT4 are normal
subclinical hyperthyroidism
Dx if TSH is low and FT4 is low
Central/Secondary hypothyroidism (pituitary failure)
Dx if TSH is high and FT3/FT4 are high
Central/Secondary hyperthyroidism (TSH producing tumor)
Which labs test for Hashimoto’s
- Anti-Tg
- Anti-TPO (also Graves
- TSH receptor antibody (blocking in hashimoto’s)
Which labs test for Grave’s disease
- Anti-TPO (also hashimoto’s)
- Antimicrosomal antibody
- TSH receptor antibody (stimulating in Grave’s)
Describe radioactive iodine uptake scans
- done in hyperthyroidism or nodule workup
- iodine collects in thyroid gland
- overactive/nodule takes up more iodine
Describe the appearance of the thyroid in a radioactive iodine uptake scan in Grave’s
symmetrical high uptake
Describe the appearance of the thyroid in a radioactive iodine uptake scan in thyroiditis
symmetrical low uptake (underfunctioning, usually not ordered for this)
Describe the appearance of the thyroid in a radioactive iodine uptake scan in Toxic MNG or Toxic adenoma
irregular/uneven increased uptake
Describe thyrotoxicosis
state of excess thyroid hormone (from gland, meds, etc?)
When is it important to include a T3 in workup of the thyroid?
when HYPERthyroidism is suspected
Describe the course of postpartum thyroid conditions
- hyper or hypo
- 2-4 weeks of thyrotoxicosis
- 4-12 weeks of hypothyroidism
- spontaneously resolves
- can treat symptomatically or with short term levo when in hypothyroid phase