<s>[INST] My friends has a yellow bruise right in the middle of his chest and its sore to the touch and everytime someone touches it he is in quite a lot of pain , he smokes tobacco and weed and also drinks he cant remember banging it on anything or knowingwhat could have caused it he has experienced chest pains before [/INST] Thanks for your question on HCM.In my opinion it is not caused by smoking. As smoking does not cause external skin damage. It causes internal body damage.So the lesion is something else. May be some minor trauma caused this bruise.So better to get done dressing.And ask your friend to quit smoking and drinking alcohol.It is not a good for health. </s>