I'm feeling a bit worried because I've been having this heaviness in my chest, but it's only on the left side. Sometimes there's a bit of pain there too. Plus, my upper back on the left side is hurting as well. It's been going on for about a year now. I did a full body checkup in the first week of January and everything came back normal. What should I do now? Who should I see for this? Are there any specific tests you recommend?