My right arm keeps twitching between my bicep and tricep. what is the likely cause and treatment?

Fasciculation: Most of the time a muscle "twitch" (or fasciculation) is totally normal. However, it can be a sign of nerve disease (lower motor neuron disease). If there was a nerve disease, i would also expect to have some evidence of sensory or strength loss on exam (and in the patient's list of complaints). Additionally i would expect reflexes to be reduced or absent. Without these, it is probably normal.

Please repost: When you write "between my bicepS and tricepS," do you mean alternating twitches, or literally between them on your arm? Because between them are only the humerus & the brachialis muscle. Your symptoms are only the beginning of the diagnostic process, not the end. Can't treat till the cause is known, & the "likely cause" is irrelevant; only the ACTUAL cause matters. See your doctor.