Three days ago I had an intense episode of tightness all over my head, neck, and shoulders and I thought I might have had a heart attack but it passed and I never had numbness or anything. The next day I got a fever and I had body aches and abdominal pain all day. I also had two brief episodes of simultaneous intense tightness and pain in my head, neck, and chest again. Today I have a fever, sore throat, body aches as well as sinus pressure. I also had several more intense pain/tightness episodes. Normally I would think this was a regular virus but the severe tightness episodes are really worrying me. Do you know what I might have?