I'm starting to get sick of my arms my left arm is weaker then my right when I try too lift weights I find myself struggling because my left arm is tremendously weak but my other arm can do it no problem, and i use machines and barbells I dont understand why my left arm is so weak, tho I'm obese 350 pounds can that have anything too do with that? just seems like my left arm doesn't want to grow muscle.

It's actually a very common problem among those of us who are very right-hand dominant; we use our right hands and arms for everything, and our left side may actually be a little underdeveloped.

I know that knowledge doesn't make it less frustrating, but all you can do is to be patient. Train both sides equally with the same weight and just let the left side catch up. When you do movement activities make sure you switch directions occasionally so that both sides get the same amount of training.

You can also do some extras throughout the day; get one of those squeezers to train the grip strength of your left hand periodically. Make an effort at home to use your left arm more. It's annoying and it takes patience, but your nondominant side will eventually catch up.

Try to minimize your use of the machines where both arms are used together. Use Barbells keeping the weight and reps and sets the same for both arms. Working in the 6-8 repetition range will build strength fastest so use a weight that your weaker arm can perform in that range. Really push the weaker arm for that last rep. Let the stronger arm cruise until the weaker one catches up.

You can also try doing drop sets where after you have worked a muscle to failure your decrease the weight by apprx. 10% then perform to failure, repeating until youv'e run out of weights.

Your left arm will catch up eventually. Everyone new to weight lifting goes through that. I just started back up after a six month hiatus due to an injury, my left arm is weaker again. Although not as bad as it was when I first started weight training, but it is weak again.
Give it time.
Robb

And some of us that have been lifting for a while still see a difference . In fact this morning we were doing dumbbell floor to overhead (snatches for those know the secret language of lifters). And I almost went to 2 different weights. By the end of the workout my left side could hardly complete the movement but my right side felt fresh as a daisy.

My guess would be to use dumbells with good form. With other bars you can still cheat as in using 1 arm more than the other.

I've had this problem too. What a trainer recommended to me was to do the exercise starting with the weaker side (in your case, your left). do as many reps as you can while maintaining good form. then you switch to your other arm, and only do as many reps as you did with the other arm.

it will take a while, but eventually things will even out.

i've used this technique with legs too (lunges, single leg squats, etc)

USE DBS. IF U SHOULDER PRESS 60 REPS WITH YOUR RIGHT BUT ONLY 40 WITH YOUR LEFT. DO 40 with your RIGHt Also.

Problem of weaker left arm is very common, it is because of lack of practice as compared to right one. You can keep putting efforts with the left arm until it get used to it. Make sure you start with minimum weight.

I found that, I don't do much barbell exercises because my right hand makes up for my weaker left arm. If you really want to get your left arm up do more sets 5-6 with your left and only 3 sets with your right. Until your left one catches up