Hematoma, by definition, is a collection of blood outside the blood vessel. Sometimes hematoma can be a simple bruise and sometimes it accumulates in a pocket.
So what I would recommend is to use ice for the few days and then start applying heat to try and dissolve the blood. It will take several weeks to dissolve.
Now, if this 'hematoma' is located right at the edge of the elbow, it could possibly be bursitis which is accumulation of fluid into a joint. This collection of fluid is soft and movable and it usually not painful.
What makes me think it can bursitis is the fact that it is not painful. Usually hematomas are somewhat painful or cause discomfort.
Of course, the only way to know is to see a doctor. Hematoma will resolve on its own within weeks (use ice for the next few days, then heat) but bursitis will not go away on its own and can actually get worse. Usually the fluid from bursitis will need to be drained out with a needle.
If the person refuses to see a doctor now, there is no urgency. He can try treating the area as if it was a hematoma but if the swelling doesn't improve or starts to get worse, he will need to see a doctor.
Hope this helps. Please let me know if you have other questions.
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