What could be the cause of my upper right arm pain?

I don't know if this could be a sign of something more serious or not.. I woke up in a lot of pain I'm not sure if I slept on it funny or what is going on but my right arm hurts a lot. I'm only 15 so I don't know about a heart attack but I'm just wondering if sleeping on your arm funny can cause so much pain.
Asked Jan 01, 2015

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