Hi! Not sure if you still log onto here but I read this and was excited to find someone who is going through the same thing as me! im 31 years old. Im a female. For about 6 months or more I have been having these weird pains in my left side of chest. Its not crushing or a squeezing sensation. Its more like a cramping sort of? and it changes in location. Sometimes its between my left armpit and nipple...sometimes its below my left breast. It also as you said...it once in awhile sends a weird sensation down my left arm into my finger tips. These events happen daily but just as yours do...seem to happen very randomly. Also, just like yours, it seems to happen when im at rest the most. When im working, moving around, ect. it doesnt seem to do this. I havent been to a doctor about it because to be honest im afraid. But i work in medical field and have discussed it with some of my coworkers and they all seem to think it isnt cardiac related due to my age and otherwise good health. I know that nowadays anyone at anytime can develop heart problems but they also told me that usually pains that come and go and last for months and months as mine have are more indicating a musculoskeletal issue rather than a heart condition. Im not sure what the heck is causing this..but if it was an injured muscle in my back or shoulder like they say i feel like it woudlve healed by now. The pains seem to be getting more frequent. And also....the area in which these "pains/cramps" are occuring is deep inside...like i cant get to it to try and massage it for relief. Nothing I do seems to trigger it...heavy lifting or exercise doesnt bring it on or relieve it when it happens. I know I should prob see a doctor but im worried they are gonna say its something serious or worse tell me there is nothing wrong and I just have to keep dealing with this and have it get worse. Just so weird that when Im at rest is when it seems to happen the most.