Joyce is seen in the clinic complaining of vague symptoms of nervousness and irritability. she says that her hair will not hold a permanent wave anymore. on physical examination, the clinician finds an irregular heartbeat and brisk reflexes. the differential diagnosis should include which of the following conditions?
a. myxedema
b. thyrotoxicosis
c. cushing's syndrome
d. pan-hypopituitarism

B. Thyrotoxicosis

Explanation:

Thyrotoxicosis means that there is too much of thyroid hormone in the body. Thyroid hormone is used to regulate the metabolic rate of every cell, and an excess in this hormone can lead to hyperthyroidism.

An irregular heartbeat may be because of the stress that extra thyroid hormone puts on the heart, in the need to supply more blood to the body. Also, relating to the brisk reflexes, thyrotoxicosis has been known to timulate twitching in patients.