I was lifting my arm over my head and I suddenly noticed a slight pain, I didnt think too much of it. With in an hour it was painful to move my arm at all. Now about four hours it hurts even without movement and there is a marble sized lump that is very tender to the touch. It is noticably swollen and slightly red. I have been trying to read about possible conditions and some are concerning but most say that it nothing to worry about. I am wondering if anyone can give me some advice or let me know if this is something that should be checked out I would really appreciate it.
Unfortunately, it is not really possible to give you too much information, since you gave so little details.
Where in your are is the pain located, is it in the shoulder, or somewhere in the upper arm, the forearm, etc? Is it constant, or only when you move the extremity? Where is the lump located? Is it painful? If so, is it constant, or only with activity? Do certain movements make the discomfort worse? What type of pain is it; sharp, burning, electrical, dull, aching, etc?
If the problem is getting worse, you may want to have your physician take a look at it. These are all things that he/she will ask. With a thorough evaluation, then the cause of your problem may be determined. It is not really possible to make a diagnosis over the internet.
Good luck. Hope you find out what is causing your problem.