Over the past few months I have been having heart palpitations, shortness of breath, chest pain, and dizziness which lasts only for a couple of minutes—maybe five at the most. I went to my doctor who told me it was probably anxiety attacks but sent me to a cardiologist for some tests. Everything came out normal, but I’m still having these episodes and they feel like something’s really wrong. I’m 30 years old and have never had anxiety problems before. How do I know this is just anxiety and why am I getting it now?