Thyroid DOs (5 questions) Flashcards
Most common thyroid conditions?
Hypothyroidism
Thyrotoxicosis (Hyperthyroidism)
Thyroid Nodules
Gender ratio of hypothyroidism?
10 women:1 man
Most common age of hypothyroidism?
>50yo
Overt vs subclinical hypothyroidism?
Overt: clinical syndrome + elevated TSH and decreased T4 or T3
Subclinical: no typical Sx but elevated TSH and normal circulating thyroid hormone
Who would you screen for thyroid dos? And how?
- Screen high risk populations
- older women
- individuals with autoimmunine disorders
- individuals with a strong family Hx of thyroid disease
- hx of radioactive iodine Tx or head/ neck irradiation
- use of med that impair thyroid fx (e.g. contains iodine – amiodarone)
- Screening test: Measure serum TSH
Symptoms of hypothyroidism
- slowing of metabolic processes: fatigue & weakness, cold intolerance, DOE, wt gain, cognitive dysfunction, mental retardation (infantile onset), constipation, growth failure
- Accumulation of matrix substances: dry skin, hoarseness, edema
- Other: decreased hearing, myalgia and paresthesias, depression, menorrhagia, arthralgia, pubertal delay
Signs of hypothyroidism
- slowing of metabolic processes: slow movement and slow speech, delayed relaxation of DTRs, bradycardia, carotenemia
- Accumulation of matrix substances: coarse skin, puffy face and loss of eyebrows, periorbital edema, enlargement of tongue
- Other: diastolic HTN, pleural and pericardial effusions, ascites, galactorrhea
What is hyperthyroidism?
thyrotoxicosis (lot o thyroid hormone) caused by excessive production of thyroid hormone
Overt vs subclinical hyperthyroidism
- overt: symptomatic, low TSH, high elevated free thyroxine (T4) or free triiodothyronine (T4) levels
- Subclinical: suppressed TSH but T4 and T3 are wnl, no Sx hyperthyroid
Who tends to get hyperthyroid (gender / age)?
women over 50yo
Most common causes of hyperthyroidism?
- Diffuse toxic (hyperfunctioning) goiter
- Graves’ disease
- Toxic multinodular goiter
- Toxic uninodular goiter
- Thyroid inflammatory diseases (e.g., Hashimoto’s thyroiditis)
- Postpartum thyroiditis, and subacute thyroiditis
Clinical features of hyperthyroidism
- heat intolerance
- warm moist skin
- increased sweating
- nervousness, irritability, eyelid retraction
- weakness, myopathy
- SOB, palpitations, arrhythmias, heart failure
- increased appetitie, frequent BMs, wt loss
- Scanty periods
- eye and skin changes of Grave’s (stare, lid lag, exophthalmos)
- hair thinning, brittle
- hyperpigmentation of skin, pruritis and hives
- onycholysis (Plummer’s nails)
Normal TSH
0.5 - 4.5/4.7
(some argue lower limit of 2.5)
Normal T3
3.5 - 6.5 pmol/L
Normal T4
0.7 - 1.4 ng/mL
What test results would you expect in primary hypothyroidism?
- Increased TSH -usually the only one ordered
- Decreased T4
- anti-thyroid Abs if Hashimoto’s
- Reduced radioactive iodine uptake and thyroid scintiscan (not usually ordered)
Clinical mgmt of primary hypothyroidism
- Eliminate thyrotoxic meds/exposure
- Rx L-thyroxine (synthetic T4)
What is a clear cut time to start pharm mgmt of hypothyroidism
TSH>10mU/L
FT4
L-thyroxine: is it necessary to start slow?
Not if young and healthy. Yes if >50 w/underlying cardiac conditions, if elderly (>70), or anyone w/severe ischemic heart disease
When would you refer for hypothyroidism?
Typically primary care, but refer if:
- 18 years old or younger
- unresponsive to therapy, or pregnant (pregnant, usually need to increase T4)
- cardiac disease, goiter, nodule, or other structural abnormality of thyroid gland
- coexisting endocrine disease (eg., pituitary disease)
Most common causes of hyperthyroid in young v elderly
- younger pts: Graves’ diz and thyroiditis (postpartum)
- elderly: toxic nodular goiter and/or occur in those being Tx’ed w/ amiodarone
What is “apathetic hyperthyroidism”?
hyperthyroidism without hyperadrenergic symptoms
How do elderly often present w/hyperthyroidism?
atrial fib, weight loss, in the absence of “classic” symptoms
What test results would you expect in hyperthyroidism?
- usually decreased TSH
- T4 and T41 usually increased
- T3 usually increased
- antithyroid Abs increased in Grave’s
- Increased radioactive iodine uptake and thyroid scintiscan
