<s>[INST] I had ARDS and was on ECMO about two years ago.  Now, out of no where, my lungs are in pain.  Horrible pain, to the point where I dont want to take deep breaths because its unbearable pain.  What could this be caused by.  I have no fever, no soar throat, or nasal drippage. Its also only on my left side that hurts. [/INST] Thanks for your question on Chat Doctor. I can understand your concern. Sudden onset severe left sided chest pain is mostly seen in heart diseases. So better to get done ECG and 2d echo first. If both are negative for cardiac pathology, no need to worry about heart diseases. Possibility of lung related causes is also less because you are not having cough or fever or sore throat. But better to get done chest x-ray to rule out lung causes because you had ARDS in the past. If all these investigations are normal than possibility of muscular spasm is more. So take painkiller and muscle relaxant Chat Doctor.  Avoid heavyweight lifting and strenuous exercise. Don't worry, you will be alright. But first rule out cardiac cause Pulmonary causes. Hope I have solved your query. Wish you good health. Thanks. </s>