25. Hypothyroidism vs. hyperthyroidism Flashcards Preview

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Flashcards in 25. Hypothyroidism vs. hyperthyroidism Deck (23):

hypothyroidism - labfinH if qprimary

1. increased TSH ( if primary)
2. decreased fT3 and fT4
3. hypercholesterolemia


hypothyroidism - increased TSH

if primary)


sensitive lab test for primary hypothyroidism

increased TSH


hypothyroidism - hypercholesterolemia is due to

decreased LDL receptror expression


hyperthyroidism - lab findings

1. decreased TSH ( if primary)
2. increased fT3 and fT4
3. hypocholesterolemia


sensitive lab test for primary hyperthyroidism

decreased TSH


hyperthyroidism - hypocholesterolemia is due to

increased LDL expression


hyperthyroidism - clinical symptoms and signs

1. heat intolerance
2. weight loss with increased appetite
3. hyperactivity, anxiety , insomnia , tremor
4. Diarrhea
5. increased reflex
6. warm moist skin
7. fine hair
8. chest pain, palpitations, arrhythmia
9. pretibial myxedema ( Graves ), periorbital edema
10 thyrotoxic myopathy ( proximal muscle weakness with normal CK)


hyperthyroidism - heat intolerance is due to

increased heat production hy


hyperthyroidism - heart symptoms

chest pain, palpitations, arrhythmia


hyperthyroidism - chest pain, palpitations, arrhythmia are due to

increased number and sensitivity of β-adrenergic receptors


hypothyroidism - clinical symptoms and signs

1. cold intolerance 2. weight gain with decreased apepetite 3. constipation 4. decreased reflex
5. Myxedema ( facial / periorbital ) 6. bradycardia, dyspnea on exertion 7. Hyporeactivity, lethargy , fatigue , weakness 8. dry, cool skin, coarse brittle hair
9. hypothyroid myopathy ( proximal muscle weakness with increased CK )


hypothyroidism - heart symptoms

bradycardia, dyspnea on exertion


hypothyroidism vs hyperthyroidism - hair

hypothyroidism : coarse brittle hair
hyperthyroidism : fine hair


hypothyroidism vs hyperthyroidism - skin

hypothyroidism : dry cool skin
hyperthyroidism : warm moist skin


Your patient states that she has been constipated, cold, and gaining weight despite decreased appetite. What is the most likely diagnosis?



A postmenopausal female has heat intolerance, weight loss, palpitations, and diarrhea. What lab findings do you expect to see?

Low thyroid-stimulating hormone (if primary disease), and high free or total T3/T4 (she likely has hyperthyroidism)


A woman has weight gain, lethargy, cool dry skin, and brittle hair; she exhibits hyporeflexia on exam. What lab findings do you expect?

Increased thyroid-stimulating hormone (sensitive for primary disease) and low free T4 (she likely has hypothyroidism)


What cardiac symptoms can hyperthyroidism cause? What can hypothyroidism cause?

Hyperthyroid: chest pain, palpitations, arrhythmia from increased β-adrenergic receptors; hypothyroid: bradycardia, dyspnea on exertion


A patient with a known thyroid condition is lethargic, with swelling in the face and periorbital region. Diagnosis?

Myxedema resulting from hypothyroidism


A patient with a known thyroid condition is hyperactive, with hyperreflexia, and has swelling on her shins. Diagnosis?

Pretibial myxedema due to Graves disease (hyperthyroidism)


How do hypo- and hyperthyroidism each affect the skin? The hair?

Hypothyroidism causes dry, cool skin and coarse, brittle hair, whereas hyperthyroidism causes warm, moist skin and fine hair


What is the mechanisms by which hyperthyroidism leads to hypocholesterolemia and hypothyroid leads to hypercholesterolemia?

Hyperthyroidism leads to hypocholesterolemia from an increase in LDL receptor expression, & hypothyroidism decreases LDL receptor expression