I would recommend that you go to see your primary care doctor
about this. Any severe or persistent pain in a defined location needs to be checked out.
Given the absence of a fall or trauma to the area, the likelihood of a fracture
of the bones is very low. That being said, there are several other conditions, including tendonitis (inflammation of the tendons) or bursitis (inflammation of the fluid-filled cushions around the joint) that could be the cause of your pain. When you go to see your doctor, make sure to mention what sorts of activities you do on a regular basis (sports activities like tennis that might involve repetitive motion at the elbow, as well as typing at a computer, etc) as these could all be clues that help them figure out what is going on.
The fact that you have some pain with straightening the arm and turn it at the wrist makes me wonder if this is not tendonitis. I say this because the tendons that control turning of the wrist are anchored at the elbow and often can become inflamed there. The lay terms for tendonitis in the elbow include "tennis elbow
" and "golf elbow." Again, please speak to your primary care doctor.