Sometimes I get shortness of breath for no reason at all. I think this is different from the MS hug (although today I had/have both) because my lungs just feel like they're not getting enough air.
Sometimes it's because of hypotension - changing from upright to sitting, or vice versa.
Today it was just a low-level shortness, that lasted until it turned into an MS hug. (Or spasms of the intercostal muscles - whatever it was, it was painful.)
Sandie - If this sensation of tightness in your chest is occurring only immediately after an injection and lasts 15 minutes or less and doesn't occur that often - then it certainly might be the Immediate Post-Injection Reaction.
However, the way you describe it, it sounds like the sensation of having somethting wrapped around your chest is lasting for long periods of time. In that case it is very likely the MS Hug.
The timing and duration will be the key to what it is.
Quix
It might be the post injection reaction that the medicine warns about. I have had 3 times so far where I had an adverse reaction. Some speculate that its from the medicine hitting a vein or artery, but no one really knows why this happens. I am glad that she had the cardio tests done. Where did she inject into? How long did the event last? Hopefully, this isn't a common occurance.
Best of luck to her!