I got ivig today and durning the treatment i noticed swelling at iv site in arm. what can i do to help the swelling and when will it go away?

Tricky: cannot say in your particular case, but generally, it depends on the amount of the swelling and other features. Can be infection, slight irritation, some/all of the injection going into the skin instead of the vein. Mostly, ice for 20 min followed by twice daily warm compresses fixes it in about 1-2 days. but if gettng worse, think need for antibiotics.