Tachycardia chest pain breathless and coughing. everyday all day for the past months, what is wrong? feels like my heart is beating out my chest.

Allergy or anxiety: If these symptoms were due to a very serious disease, such as pulmonary embolism, heart attack, aortic dissection, pneumonia, etc., the symptoms simply do not linger for months without a catastrophic event occurring. Plus, 23 year olds simply do not have blockages in their coronary arteries or heart attacks. You need to have an ekg, chest x-ray, blood work, and a good physical exam to confirm.