Dispy,

Where do you do your strumming motion from, the wrist or the elbow??

If its from your elbow, do you get stressed out when your trying playing something alittle more difficult or are you able to be relaxed and stay relaxed??

If you get alittle stressed out, you many have strained a tendon in the elbow. Just relax for a few days and see if the pain goes away. Always try to stay relaxed when you play.

Is the pain on the outside (boney side of the elbow) or on the inside?? If it's on the inside, one cause may have been from trying to lift (in a curling fashion) something that was alittle to heavy for your arms. If it's on the outside, if could possible be from playing guitar but only if you strum from the elbow.

Now if your strum from the wrist, you probably hurt it doing something outside of playing guitar. Maybe you sleep on it wrong or bumped it. Another way is you may have over-extended your elbow somehow. The pain would be on the outside on the elbow if this was the case.

Anyways, if you think it may have possibably been from any of these. Just let it relax for a few days and see if the pain goes away. If not, you should see a physician asap.

Hope that helps man.