Im 37, 62kgs, no real history of medical problems. Cholesterol was normal last check (Sept), exercise regularly.  Used to smoke but quit last year.  I have a constant pain in my chest and have been really tired for the last week or so.  I also have some much milder soreness in my back, shoulders and neck, but have attributed that to longer hours spent working at a computer recently.
Thanks for your question on Chat Doctor. I can understand your concern. Since your cholesterol is normal, and you do regular exercise, possibility of heart related chest pain is less. But as you are past smoker, better to get done ECG to rule out cardiac chest pain. If ECG is normal then no need to worry about heart diseases. You are mostly having musculoskeletal pain due to prolonged sitting against computer. This can cause stiffness of back, neck and intercostal muscles. So better to avoid prolonged sitting. Sit for 1-2 hours and then stand up, move around for 5-10 minutes and then again sit. This will be very helpful in your case. Also sit with proper back support. Avoid awkward movements like bending or stretching while sitting. Apply warm water pad on affected areas. Take painkiller like ibuprofen. Don't worry, you will be alright with all these. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.