<s>[INST] Hello I am 33 years old, 345lbs and I quit smoking about 2 months ago. By quitting smoking I discovered about 20 little swollen muscles that go underneath both my breasts and extend from one breast to the other. It also has caused my sternum to have a little discomfort. I was told this type of aching in my chest area would last about 3 months due to side effects from quitting smoking. I recently went to the doctors just to make sure this problem wasn t my heart. I only had a small high cholesterol problem. All other tests I took I was ok with. This also muscle ache seems to flare up more around at nightime then any other part of my day. Thanks for helping me with this as this is causing multiple nights of tossing and turning. I just didn t want meds to be the source of everything. If there is anything you could recommend I d be greatly appreciative. Thanks! [/INST] Hello, I appreciate your efforts. Such type of aching is due to withdrawal of toxins from your body. The swollen muscles which you are feeling under your breast may be tender costochondral junctions of ribs or intercostal muscles between ribs. These are normal anatomical structures. The intermittent flare up of aches can be controlled with some analgesics which you may ask from your doctor. I shall advice you to also start meditation and mild stretching exercises which will help you gaining strength during this period. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Mukesh Tiwari, Orthopedic Surgeon </s>