Is Nausea associated with a seroma?

Thank you for sharing your question and I am sorry to hear of your seroma and nausea.  Seromas in general are not associated with episodes of nausea, while nausea after four months would also be unusual from surgery.  I would advise seeing your plastic surgeon for an in-person evaluation, treatment of any seroma, and discussion as the possible causes of your nausea.  

Seromas are not usually associated with nausea but on some occasions can be associated with a feeling of bloating or fullness.

You need in person scan of abdomen to see if retained seroma, hematoma, abscess. Also seek in person send opinion from PS.

Nausea with seroma probably indicated mold biotoxin disease along with blurred vision and sometimes dizziness.  You will need antifungals along with the removal of the seroma and any scar capsule that has formed.