How do I tighten loose skin after something like swelling or weight loss? Will it just happen naturally?

A lot depends on age  When I was 24 I had a baby and during my pregnancy I was eating for 7  I gained 60 pounds  Then I lost all that weight and within a very few months my loose skin was back tight and where it was supposed to be  At 52 I had a hysterectomy and I'm convinced the not only removed the usual parts, but removed my metabolism as well    After several years I lost 70 pounds (not nearly all the weight I gained)    That was back in 2012  Even though I work out 9 times a week I STILL have a "apron" of skin from my stomach that hangs  Its alabout gravity and age