I am a 28 year old female, 5 feet 8 inches, 190 pounds. I am a smoker, I don t drink. I don t have a significant medical history. I am experiencing sharp, burning pain 7/10 along my sternum. It started about 5 hours ago. It hurts most when I completley relax, exhale or cough. I am slightly nauseated. I had sinus congestion earlier this week, but not today. About a year ago I went to the emergency department and was diagnosed with costochondritis. This feels similar but is in a different spot and hurts much worse. Any ideas?Thank you!