Is the joint hot? Does it feel as if there may be fluid on the joint?
My entirely non-professional opinion would be that you're looking at a non-inflammatory arthritis, basically, Osteoarthrits. You need to see a doctor about it, but for the time being, 400-600mg of Ibruprofen, 1g of Paracetamol, and whatever strength of Codeine you can get with the Paracetamol OTC (8mg usually), every 4 hours, would be the most effective thing at keeping the pain at bay.
There isn't much in the way of long-term treatment for this sort of arthritis, and it tends to be palliative. Stronger NSAIDs than Ibruprofen will probably be prescribed, like Diclofenac, which I find very effective, and (unless you're in the states) Arcoxia is a good NSAID. if the pain continues to be an issue, there is of course opiates - but these are best avoided unless really neccessary. As/if the condition worsens, there are surgical options available to you which can significanly reduce pain.
Before jumping to conclusions, it is important that a qualified physician rules out other potential illnesses which can present with arm pain, of which there are a few. That said, arthritis has a strong hereditary component, so it does seem likely.
None of the above constitutes medical advice, it is merely speculation, so don't for heaven's sake act on whatever I say and then die, cause I'll feel bad.
All the best, hope you sort it out
Paracetamol = APAP, or Acet--blahblah-phen. Sorry I can't spell the American name, as I've never used it. An iranian friend shouted at me the other day for using "Paracetamol" as he had no idea what it was!
21, Male, England.
Dx: Psoriatic Arthritis, Fibromyalgia, Dyspraxia
Rx: 50mg Etanercept (Enbrel) Sub-Cut Injection, 7.5mg MTX, 25mg Amitriptyline
Oh, and plenty of Tramadol, Dihydrocodeine, Domperidone, Hydroxyzine, and Scotch
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