Hi, The commonest cause I can think about such problems are as follows: Costochondritis. Muscle strain. Viral infection as you have chills too. Since there are no other symptoms that you have mentioned the commonest cause can be costochondritis wherein there is inflammation of the joints between the sternum and the ribs. The stress and anxiety can add on to the problems. I would advise you the following in such a situation: Consult your Doctor to see for local tenderness, clinical examination and investigations if needed. Take an anti-inflammatory medications like Ibuprofen and oral steroids if you need to have early relaxation. Also watch for a cardiac and esophageal cause such as GERD. Get done cardiac tests like EKG and Echocardiography. Take a PPI like Omeprazole. Take rest, avoid stress and anxiety. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. T Chandrakant, ENT & General Surgeon