My left index finger started twitching some time in the last 72 hours. i haven't experienced any other weird or unusual symptoms. is this something i should be worried about? what could be the potential cause? should i see a doctor?

Twitching: Such localized twitching is most often a nonserious irritable nerve or muscle or a result of an overuse of the finger. If it persists, avoid caffeine but if it (and/or other areas twitch ) continues for a more prolonged time, possible causes are deficiencies of calcium, magnesium or an electrolyte imbalance. A neurologist would be best to evaluate and advise you.