Lateral epicondylitis, (aka tennis elbow) is a common cause of elbow pain. People describe the pain as an ache located in the lateral side of the elbow. Normal activities such as gripping or lifting can become extremely painful.
Although the “-itis” in the name would suggest it, this is not an inflammation problem. In fact, it is the lack of healing that accumulates and causes pain in the tendons of the elbow. Naturally, you don't want to take anti-inflammatories or cortisone injections because those would discourage inflammation which is the first stage of healing. This problem will tend to go away on its own, but it can take over a year.
By using ultrasound, we can see the damaged areas of tendon. These appear as dark “hypoechoic” areas of tendon near their insertion on the bone. 
One treatment option is a platelet rich plasma (PRP) injection. This is a procedure where a person’s blood is drawn and spun in a centrifuge to isolate the the healing factors and platelets. By injecting those healing factors back into the elbow area, it is possible to stimulate the tendon to regenerate. Results can be varied but recent studies suggest it is about as effective as surgical procedures. Here is a video from one company who makes a PRP system.
