I started having sharp pain in my left shoulder yesterday while laying in bed and I would feel the pain every time I took a breath in so I started having shortness of breath to reduce the pain. The pain was located in the front of my shoulder and not on my back. At first I thought it was something related to a tendon or a nerve being pinched because I had lifted some curtains the previous day and did other house work. However, when I woke up today, I had severe sharp pain in my shoulder and it seemed to be moving toward my back, but still mostly on my front side. It started to become more dull of a pain after moving around and going to class. When I came back from class, I ate a burger and had a soda and the pain was excruciating and very severe that I could barely move my arm. When I started burping, it was the only thing that gave me some pain relief. Eventually, it became a dull pain that I only notice when I take a breath and it doesn't bother me unless I eat or try to lay down. I never been diagnosed with any conditions such as GERD, but I currently have a diet with a lot of fast food and I do have a high triglyceride level (200-215 typically), otherwise everything else about me is normal (might be overweight, I weigh 205lbs at 6'1 ft tall). There's family history of diabetes and heart disease (I have neither). I'm not taking any medication. Is there a way to treat it in the meantime, or should I go to a ER? This is the first time I've experienced these symptoms. Right now I'm thinking it could be - tendon/muscle strain or tear, heart related, or GERD, but not sure what it is. No other symptoms related to GERD that I know of.