AANP Family Nurse Practitioner (FNP) Certification ExamAssessmentMedium
A 52-year-old female presents with a 3-month history of progressive fatigue, generalized weakness, and muscle cramps. She also reports constipation and occasional heart palpitations. On physical examination, her deep tendon reflexes are diminished, and she has periorbital edema. Her current medications include a multivitamin and omeprazole for GERD. Which of the following diagnostic tests is most appropriate to order initially?
- ASerum potassium and magnesium
- BElectromyography (EMG)
- CThyroid stimulating hormone (TSH)
- DSerum calcium and parathyroid hormone (PTH)
Show answer & explanationAnswer & explanation
Correct answer: C. Thyroid stimulating hormone (TSH)
The constellation of symptoms including progressive fatigue, generalized weakness, muscle cramps, constipation, periorbital edema, and diminished deep tendon reflexes are classic signs of hypothyroidism. TSH is the most appropriate initial screening test for thyroid dysfunction.
Why the other options are wrong
- A. Electrolyte imbalances can cause weakness and cramps, but the other symptoms (edema, constipation) are less typical.
- B. EMG is used to evaluate nerve and muscle function, but a metabolic cause like hypothyroidism should be ruled out first.
- D. While calcium and PTH can cause weakness, the periorbital edema and constipation point more strongly to thyroid issues.
Hypothyroidism Initial Workup
Hypothyroidism presents with a wide range of non-specific symptoms including fatigue, weight gain, constipation, muscle weakness, and edema. TSH is the primary screening test.
- Common symptoms: fatigue, cold intolerance, constipation, dry skin, weight gain.
- Physical signs: bradycardia, periorbital edema, diminished DTRs.
- Initial diagnostic test: Thyroid Stimulating Hormone (TSH).
Memory trick: When the body feels sluggish and slow, check the hormone that makes it go!