A 30-year-old woman presents to your office with the chief complaint of urinating more frequently. Over the last several years she has noticed a weight gain of 40 lbs.

 A 30-year-old woman presents to your office with the chief complaint of urinating more frequently. Over the last several years she has noticed a weight gain of 40 lbs. She has tried numerous diets. The patient's only other pertinent history is that she was told to watch her diet during pregnancy because of excessive weight gain. Her baby had to be delivered by cesarean because he weighed more than 9 lbs. Her family history is not known, as she was adopted. What is the probable diagnosis? What are other possible diagnoses? At this stage of the case study, what diagnostic studies and basic treatments are most appropriate to order and why?