I'm feeling a bit worried about a sensation I have in the middle of my chest, like something might be blocked. A few days ago, there was pain, but now it's just this light pressure, especially when I lay down. I also have this discomfort in my left breast, like something is blocked, but I can't pinpoint exactly what it is. Could this be something serious, like a blood clot in my lungs or pulmonary embolism, or maybe myocarditis? The weird part is that exercise or taking a deep breath doesn't seem to bother it, but laying down sometimes makes me feel this fullness or pressure. What could it be?

It is important to evaluate your symptoms further to determine the underlying cause of your chest discomfort. The sensation of something being blocked in the middle of your chest, along with pressure and discomfort in the left breast, could be due to various reasons. While it is difficult to provide a definitive diagnosis without a physical examination and additional tests, the symptoms you described could potentially be related to conditions such as gastroesophageal reflux disease (GERD), musculoskeletal issues, or even anxiety. Given that you do not experience worsening symptoms with exercise or deep breathing, it is less likely to be related to a blood clot in the lungs (pulmonary embolism) or myocarditis. However, it is still important to seek medical attention for a proper evaluation and diagnosis. I recommend consulting with a healthcare provider for a thorough evaluation, which may include a physical examination, imaging studies, and possibly an ECG to rule out any cardiac issues. In the meantime, you can consider taking over-the-counter antacids for possible GERD symptoms and practicing relaxation techniques to help with anxiety-related symptoms.