15yr old says arm hurts from inside out trouble moving arm

My 15 yr old woke up with her arm hurting. She says it feels like the bone hurts from the inside and is having trouble moving it. I am going to take her to the dr on mon. But I am wondering if I shoud take her to the er now or what it could be. She did not hurt it in any way.

[sweetpea03]

Which arm is it? If it's the left arm, it may be more serious than if it were the right arm. Left arm pain can be a sign of a heart issue with little blood flow. It also depends if the pain gradually came on or was sudden? Did she just get it after she woke up?(may have slept on it weird). Hope she's feeling better today.