How Does Parathyroidism Reflect On Weight Gain?

I am in the process of getting lab results for possible parathyroidism. The dr. mentioned surgery today, but being 43 and weight is not what it used to be, I am already scared of gaining weight. I've always been fortunate with my weight with it remaining within 5-10 pounds since age 25, but I am older now. 10 pounds over weight is my absolute max. I am scared...and a little nutty about my weight because I am only 5'2".