I have a twitching pulsing vein visible in my left palm. should i worry or is this a normal annoyance?

Pulsing in the Palm: What your describing is likely not a vein but an arteriole or small artery just below the surface of the skin in the palm. This is normal as there are 2 arcs of branching arteries across the palm that give rise to the smaller arteries going to each finger. The veins are more superficial and you may see these more readily, but it is the arteries pulsations that you're feeling just below.

Twitches go away: Give it time, but if the twitch doesn't go away then get it checked out. Most twitches do go away spontaneously. There might be an irritated nerve from over use or trauma, but the true cause of twitches is usually not discovered and the twitch goes away by itself. If it continues then see a neurologist or orthopedist.

Maybe ulna A aneurys: Does it pulse with your pule rate. If so it could be an aneurysm. The most common one in the palm is an ulna art, aneurysm, caused as a result of hypo-thenar-hammer-syndrome.Caused by repeat use of palm to hammer like an air-conditioner installer i treated who used palm to hammer into place air-conditioners.Duplex is best initial diagnosis. If not synchronis w pulse is muscle twitch, don't worry.