Hello! I had been diagnosed with Costochondritis about 2-3 weeks
Do an MRI.
Hello dear, welcome to Ask a doctor service.
I read your query and here is my advice.
There are not any special tests for costochondritis but your doctor should have performed you ECG, or heart ultrasound, x-ray or MRI or CT scan to check for heart and lungs problems.
The pain of costochondritis can be similar to heart attack or lung problems or even stomach pain.
The spitting up blood is not related to costochondritis. It can be related to lung disease.
I can recommend you to do an MRI to check for lung issues.
Hope I have answered the question.
Let me know if I can assist you further.