hypothyriodism

Question 1

what are the primary causes of hypothyroidsm

Answer 1

cogenital - atrogenic doesnt form at all or maldevelopment

idodine deficancy normal = 100-199 g l in pregnancy 150 -249

autoimmune hashimotos diease - antibodies attack the thyriod

dyshormonogenesis just means:
A genetic defect where the thyroid can’t properly make thyroid hormones (T3/T4), even if the gland is physically normal.

• trapping normally, the thyroid “traps” iodine from the blood (using a transporter called NIS – sodium-iodide symporter).
  → In a trapping defect, the thyroid can’t absorb iodine properly, so it can’t even start making hormones.

Organification defect
→ After trapping, iodine must be attached to tyrosine inside a protein called thyroglobulin — this step is called organification (catalyzed by an enzyme called TPO — thyroid peroxidase).
→ In an organification defect, iodine is trapped but can’t get attached to tyrosine, so no T3 or T4 is made.

drugs
latrogenic - due to radiations or sugery head and neck cancers

sub acute thyroditis - after a virus
thyroiditis post partum

Question 2

what drugs can lead to hypothyroidsm

Answer 2

lithium amiodrone interferon

Question 3

what is the difference between primary secondary and tertiary hypothroidsm

Answer 3

✅ Primary hypothyroidism = the problem is in the thyroid gland itself.

✅ Secondary hypothyroidism = the problem is in the pituitary gland (which makes TSH).

✅ Tertiary hypothyroidism = the problem is in the hypothalamus (which makes TRH).

Question 4

secondary causes

Answer 4

Pituitary tumors (adenomas)

Pituitary surgery (damage)

Pituitary radiation

Sheehan’s syndrome (postpartum pituitary infarction)

Infiltrative diseases (e.g., sarcoidosis, hemochromatosis)

Trauma to the pituitary

Question 5

tertiary

Answer 5

Hypothalamic tumors (e.g., craniopharyngioma)

Hypothalamic surgery or radiation

Infiltrative diseases (e.g., sarcoidosis, Langerhans cell histiocytosis)

Traumatic brain injury

Question 6

secondary = low TSH because pituitary broken

Tertiary = low TRH → low TSH → low T3/T4

primary = high TRH hight TSH and low t3/t4

Question 7

what is the treatment for hypothyriodsm

Answer 7

levothyroxine

Question 8

what is subacute thyroidism

Answer 8

normal T3/t4 (10-25)
high TSH

Question 9

do you treat subacute thyroidism

Answer 9

repeat after 2-3 months (TFT’s) TSH and T4 and maybe thyroid peroxidase most the time normal

if TSH is still high but less than 10 and they have symptoms trail levothyroxine stop if there is no improvement of symptoms

definitely treat is the patient is pre - pregnant or pregnant

Question 10

if patients have hypothyroidism and there TFT are normal and on meds consider other diseases

Question 11

normal TSH

Answer 11

0.4-4

Question 12

prepregnancy and thyroid targets

Answer 12

trimester 0.1-2.5
trimester 0.2–3.0
trimester 0.3–3.5

increase the dose regular monitoring once a month until 20 weeks
reduce two weeks after birth

Question 13

what to do if patients have palpitations = subclinical hyperthyroidism (20%)
suppressed TSH can cause a three times more like to have AF

Answer 13

Lower the levothyroxine