Hello, @oliviah9. oliviah9

I hope by now they have figured out the cause of your symptoms. Please update if you can. I had developed shortness of breath and chest pain and was told it was anxiety. Three weeks later I was rushed to the hospital with massive pulmonary emboli. As you had gone diving, you may have developed something in your lungs or the long trip may have caused a DVT that has broken up and moved towards your heart and lungs. My heart rate had increased, which was normally 60 or less, but they didn’t attribute anything to the heart rate that increased over 100. I did end up developing anxiety, as I had struggled so badly to breathe. Medicine may help anxiety, but I found the best thing was to practice various techniques that I learned from my PTSD specialist. Most of it is just a form of distracting you from the moment that is causing you anxiety. Some of the strategies are to close your eyes and think of some place that is relaxing and then start gong through a process telling yourself that you can feel your shoulders relaxing, your arms, etc all the way to your toes. Then focus on your heart beat and breathing, still picturing that relaxing environment. Sometimes you can’t sit still and close your eyes to go through the entire process, so a quick distracting technique is to look for a certain number of visuals things, smells, sounds, etc. You can also count in your head and take breaths as you do it. I’ll count 1-2-3 and take a breath and hold then breath out at the same 1-2-3 rate. It helps control my breathing so I don’t hyperventilate and panic. I don’t like how medicines make me feel, but sometimes they are helpful during rough times when nothing else works.