Final answer:
The nurse should instruct the client taking estradiol to monitor and report headaches as an adverse effect.
Step-by-step explanation:
The adverse effect that the nurse should instruct the client taking estradiol to monitor and report is headaches.
Headaches can be a common side effect of estradiol, a hormone replacement therapy commonly used to alleviate the symptoms of menopause. While headaches may not be a severe side effect, they can still cause discomfort and should be monitored and reported to a healthcare provider.
Other potential side effects of estradiol include hypotension (low blood pressure), bruising, and oliguria (decreased urine output), but headaches are more commonly associated with this medication.