6 weeks post op tummy tuck with muscle repair and lipo. How do I know if it's swelling or a seroma?

It is common and expected to have swelling at this point in recovery. However, if you have concerns or notice changes it is always best to check with your surgeon. If the swelling has been there from the beginning and hasn't changed it is likely typical swelling. If it is new or growing larger it warrants further assessment.

Clinically, an exam would be necessary to sort these things out. Swelling after TT usually lasts 3 to 6 months, but most of the swelling is gone after a few weeks. Healthy people at their ideal weight should have the best overall recovery, but some of this will depend upon the surgical technique and adherence to postoperative protocols.  I always advocate following your PS's post-operative protocols as he/she knows how you are healing and is responsible for your recovery.Kenneth Hughes, MD, ABPS Board Certified Plastic SurgeonLos Angeles, CA

Hello dear!!
Thanks for the question and provided information as well. 
Unfortunately, without pictures, it is very difficult to give you a proper answer. If you have any concerns, please follow up close with your plastic surgeon.
Good luck :)

Seroma is not something that can be easily known through photos. It would require an in-person examination. Seromas are not uncommon to post op tummy tuck and can be resolved by using drains in severe cases. Your surgeon would be the best resource of information as each has his/her own postop protocols. Compression garments are usually worn to decrease swelling in the first few weeks. However, it would be your surgeon who will be best to ask when the garment can be removed. 

Thank you for your question. Your surgeon is the best one to answer that question as it requires an examination. Sometimes it is not the easiest to decide, and an aspiration can be performed safely if needed.